Pizza's gone grown-up. Twenty years ago it was okay for teens to eat pizza, but if mom and dad wanted to indulge, they had to take the kids along or feel out-of-place at the pizza palace. No longer.

While pizza remains the favorite adolescent entree (teens, a poll shows, prefer pizza to sirloin), more and more adults are munching it too.

It can still be bought at the sleazy pizza parlor where kids play pinball till the pie comes from the oven; but now, unabashedly, many restaurateurs serve pizza on tables covered with real cloth to diners who use knives and forks.

The Yellow Pages here list hundreds of establishments under the heading "pizza," and each one -- like each of the thousands across the country -- has a band of loyal followers.

One expatriate Chicaoan, so the story goes, was so attached to the deep-dish variety served up by Pizzeria Uno that whenever he returned to the Windy City he would pack a dozen in dry ice to take back to his new home.

A pseudo-scientific, and highly caloric, sampling of pizzas in this area turned up none that would prompt the fits of fealty accorded the product of Pizzerira Uno. The quest did, however, turn up a number of establishments that deserve a loyal following, as well as a number of pizzas that were at best mediocre and a few that were -- well, downright unpalatable.

Unfortunately, for each pizza there seems to be a fan. Years ago we knew we couldn't talk politics or religion; now we know we can't talk pizza, either.

Be forewarned: if you try a similar sampling, each of your friends, too, will have his or her favorite pizza. And rest assured that most of them will have made their judgments without resort to their palates or tastebuds.

Apparently an undercooked pizza with a crust of cardboard and six ounces of olive oil in lieu of tomato sauce can take on the dimensions of a mighty culinary creation when shared with a first love.

This taster's tastebuds were uncorrupted by such blind romance, except, perhaps, for a love of the creation itself: a dish devised by Italian peasant women as an inexpensive way to feed their impoverished families.

It's at its simplest that pizza's at its best -- a dough crust topped with tomato sauce, cheese (mostly mozzarella), some oregano and perhaps a little oil. It should be baked until the cheese is bubbly and the crust cooked thoroughly.

Unsurprisingly, American -- who set Mussorgsky to a disco beat -- could never be content with a food that simple. They delight in adding any number of garnishes to the topping, such as sausage, green peppers, bacon, onions, anchovies, black olives and mushrooms. Indeed, mushroom consumption has, er, mushroomed in the last decade, largely because of its popularity as a pizza topping.

One West Coast entrepreneur offers up a pizza with a topping of Canadian bacon and pineapple; another devised a pie that calls for diced earthworms. And white pizza -- garlic, oil and herbs baked on a standard crust -- has become fashionable at a few establishments, although it's far less popular than its cheese-and-tomato cousin.

Pizza-fanciers tend to break down into two main groups: those loyal to the thin-crust, or Neapolitan, version and those partial to a thicker-crust, Sicilian pizza.

A variation on Sicilian pizza is the super-thick-crust, or Chicago-style, pizza that comes in a dish rather than on a flat metal tray.

While pizza may be the snack of choice for the middle class, it's a recent addition to the American palate, traced by most pizza historians to the World War Ii GIs who returned from Italy with a taste for the product.

Today, more than $4 billion a year is spent on pizza. It could be $8 billion -- there are no reliable figures. Today, fast-food chains such as Shakey's and Pizza Hut turn out standardized pizzas that have all the panache of the hamburgers churned out by chains such as McDonald's or Burger King.

Like the hamburger purists who plead with the counterman to hold the pickles and the lettuce and the mayo, the authors are picky when it comes to pizza. They confined their sampling to plain cheese pizzas -- topped only with cheese, tomato sauce and herbs -- and washed down the morsels with cola rather than palate-numbing beer.

It was an intensive search, confused by the touting of friends and the myriad entries in the Yellow Pages. We called a halt after 17 visits, for the good of our waistlines as well as out palates.

So don't be disheartened if your favorite place is not on the list -- neither are ours. We remain partial to the pies served up at the Home Run Inn in Chicago and Dido's in Bayonne where each of us shared a pizza with our first high-school sweetheart. PIZZA PLACES ARMAND'S CHICAGO PIZZERIA, 4231 Wisconsin Avenue NW. The sub-shop folks were the first to introduce the deep-dish variety in the area. It's a creditable attempt, though still a far cry from Pizzeria Uno. A large pizza will easily satisfy four: It's well cooked, with ample amounts of cheese (the menu warns not to ask for extra cheese: ("Our pizza starts with triple cheese"). The sauce is slightly on the sweet side and tends to gravitate toward the center. Eat the pizza hot: It does not cool well. A. V. RISTORANTE ITALIANO, 607 New York Avenue NW. The service often leaves much to be desired, but the pizza is among the most distinctive in the area. topped with perhaps the least amount of cheese and sauce of any pizza sampled, it's an immediate put-off to the more-is-better school of thought. But it fares well. The sauce, spicy and made with whole tomatoes, overshadows the well done, tangy cheese. The crust is crispy on the bottom but light and airy otherwise. GENO'S RESTAURANT, 1300 King Street, Alexandria. The large pizza here is small, but so is the price. The pizza has all the pizazz of a store-bought frozen pie: The crust is thin, the sauce hardly spicy and the cheese basically tasteless. The sauce was distributed unevenly, although the pizza itself was well cooked. Service is friendly and quick. A companion had eggplant parmegian. She said it was good. Gusti's restaurant', 1837 M Street NW. Gusti's was one of the first restaurants to take its pizza offering seriously, although the version it purveys is hardly memorable. The sauce is bland and there's not a lot of it. There is however, a generous portion of cheese, and that was tasty. The cheese was cooked properly, although the crust was underdone and doughy in parts. Overall, the pizza was dry, so expect to order two drinks. LEDO RESTAURANT, 2420 University Boulevard, East Hyattsville. This pizza landmark near the University of Maryland s often crowded, but the wait is worth it. The pizza is square, and the large one takes two trays. The restaurant prides itself on homemade crusts and sauce. The crust is flaky, reminiscent of a peach piecrust rather than a traditional pizza crust. The sauce, which dominates the pizza, is sweet and used liberally. It's often spread unevenly. The pizza is filling. Be forewarned: The place is often crowded and there's little room to wait inside; the line often stretches many yards outside, an inconvenience in inclement weather. LEONIE'S RESTAURANT, 1500 University Boulevard, East Langley Park. Another popular University of Maryland haunt not far from Ledo's, Leonie's also serves square pizzas. The restaurant offers both thin-crust and Sicilian-style pizza. We sampled the thin-crust, which was well done but salty. The pizza was oily as well and the sauce somewhat bland. The cheese, however, was ample, tangy and well distributed. The crust was doughy in parts. The concoction holds up better than most after it cools. LUIIGI'S PIZZERIA RESTAURANT, 1132 19th Street NW. Luigi's, one of the better-known pizza places in Washington, bills itself as having the "Best in Town." There's an element of self-delusion to that statement, although the pizza is good. It has a generous topping of cheese, well distributed and tasty; the sauce is tangy. But for those of you who like to eat with your hands, beware; The pie is gooey and hard to pick up. The crust is thin, although puffed up around the edges. It's well cooked and plays little role in the pizza, neither interefering with nor adding to the more memorable cheese-tomato topping. MAMMA LUCIA RESTAURANT, Prince George's Plaza, Hyattsville. This is a throwback to the pizza parlor of West Side Story vintage. Its silverware -- when you ask for it -- is plastic, its tables Formica, and the soft drinks come in cans. But the pizza is good. The place offers both thick-and thin-crust pizza; we tried both. The thick-crust was light, but so was the cheese topping. The sauce was tasty, although not too spicy. The cook was heavy-handed with the herbs in some spots, more moderate in others. The thick-crust pizza was square, the thin one the traditional round. As with the thick-crust pizza, the sauce and cheese were blended together rather than put on in layers. Both pizzas were somewhat bland, but the were well cooked and appetizing. An out-of-the-way find. MANNY'S RESTAURANT, 4237 Wisconsin Avenue NW. Manny's is just up the block from Armand's and if the line outside the Chicago Pizzeria is exceptionally long, you might try here. Manny's dishes up a generous helping of cheese and tomato sauce, but it's a generous helping of blandness. The crust, which the restaurant says is fresh-rolled, was doughy and broke under the weight of the topping when picked up. As the pizza cools it becomes very chewy. MINO'S RESTAURANT, 1204 20th Street NW. This is a little restaurant (only 32 seats downstairs), that serves a mediocre pizza. The sauce is quite tasty -- tangy with a hint of sweetness -- but the cheese is almost tasteless. The crust is thin, very crunchy and hard to cut. Service, however, was friendly and prompt. PICCO'S RESTAURANT, 10403 Main Street, Fairfax. The restaurant offers a giant list of toppings, including what we presume to be a few bogus ones, such as toothbrush bristles and lizard legs. But don't be put off -- the toppings are not there to cover up an inferior pizza. Although the pie was a little overcooked around the edge and undercooked in the middle, Picco's turns out a light, mellow pizza that may not send the true fan into fits of ecstasy, but will satisfy all but the most critical. The restaurant is small and often crowded.The best time to arrive, as we did, is in the middle of a Redskins game on a Sunday afternoon. PINES OF ROME, 4709 Hampden Lane, Bethesda. Pines is gaining a reputation as one of the better Italian restaurants in the area, but, at least on the night we visited, its cheese-tomato pizza was not up to snuff. Its white pizza, however, was well done. The crust on the white pizza was well cooked, pliable without being doughy. On the other hand, the traditional pizza was burned in many spots, the tomato sauce had the punch of stewed tomatoes, the cheese was unmemorable and the spices were unevenly distributed. Stick with the white pizza as an appetizer and order the calamari. PIZZA 'N' PASTA, 2131 Wilson Boulecard, Arlington. This restaurant also offers both Sicilian and thin-crust pizza (which they bill as New York style). We chose the New York style, and were pleased. The crust was chewy but well cooked. The cheese, in sufficient amounts, was browned but not burned; it had a faintly sweet character to it. The sauce, on the other hand, was sparse and what there was of it tended to settle toward the middle of the crust. The sauce itself was undistinguished but palatable. It's a very edible pizza. PIZZA HUT. We went to the Pizza Hut at 5731 Lee Highway, Arlington, but the chain has restaurants all over the area. The menu promised a "thin and crispy" crust. The crust came as advertised, with all the taste and consistency of matzo. The sauce was spicy, with small chunks of tomato, but there wasn't much of it. There was, at least, an adequate amount of cheese but it was overcooked, almost burned. Service was poor on the night we were there; It took nearly 45 minutes for the pie to arrive, that's not overly long for a deep-dish Armand's pizza, but way too long for a fast-food chain. QUEENSTOWN RESTAURANT, 3185 Queens Chapel Road, Mount Rainier. Just over the District line, the Queenstown Restaurant had been turning out "Philadelphia Style" pizzas for years. The pizza is simple, straightforward and well done, although exactly how a Philadelphia pizza differs from a standard thin-crust pizza is unclear.It looks and tastes little different from the standard variety. The crust is handmade in a Philadelphia bakery, the menu says, which means to us that the crust is not fresh; but Queenstown produces a light pizza, properly cooked with an appetizing cheese-and-tomato combination. It's not worth circling the Beltway for, but if you're in the neighborhood, drop in. RUFFINO'S SPAGHETTI HOUSE, 4763 Lee highway, Arlington. The service was swift and efficient. The pizza left much to be desired. The cheese was improperly melted, with individual strips of mozzarela still visible when the pie was served; they should have melted into a smooth topping. The sauce was tasteless and there was little of it. The pie, however, was evenly cooked. SHAKEY'S, 7434 Riggs Road. Adelphi. Shakey's, like Pizza Hut, is a chain with several branches in the Maryland and Virginia suburbs. It serves both thin and thick-crust pizzas and offers a wide variety of additional toppings. Take the toppings: They might conceal what was otherwise a bland, oily, overcooked pie. The pizza is served cafeteria style: order and pay at one end of the line, pick it up at the other when your number is called several minutes later. Order and pay for your drinks at a third spot. There's no silverware and you must eat off napkins.Calling Shakey's product a pizza is akin to calling a frankfurter a "round steak." The soft drinks are the best deal here.