WITH A big, spirited holiday weekend on the way, what better way to celebrate the Fourth than with some of this country's least expensive, yet totally meritorious generic wines.

Most of the California wines consumed in this country are the ubiquitous blended wines which are called "generics." California excels in producing these jug wines, and the ingredients for their success include inherent freshness, fruitiness and the increasing trend by producers to make wines drier on the palate. Here are my favorite jug wines, which should please both the palate and the purse while serving quite admirably at your weekend barbecue or picnic.

But first, two caveats: Be sure to purchase your jug wines from a retailer who has a quick turnover of inventory, as all jug wines are stored standing up, thereby increasing the chances of an oxidized, stale bottle of wine. And don't hesitate to chill your red jug wines, since most of them are made in a soft, fruity style, and red wines in the heat of the summer are simply more refreshing if served at slightly chilled temperatures. The White Jugs

* 1980 Beringer Chablis ($2.99). This refreshingly fruity, medium-bodied, dry white wine has more substance than one usually expects in a jug wine. In fact, the flavors border on being a bit fat and intense for a jug wine, but who can argue with the fresh fruitiness and price?

* 1981 Chateau St. Jean Vin Blanc ($5.99). One of California's finest wineries, Chateau St. Jean consistently turns out quality wines, and their low-end white table wine is no exception. This new release is tart and fresh, with lively fruit, crisp acidity, medium body and bone dryness. If you like your jug wines slightly on the austere style, this vin blanc is highly recommended.

* 1980 Parducci White Table Wine ($2.99). Parducci makes a lot of wines, most of them of sound quality. This low-echelon white table wine has a very perfumed and flowery bouquet, is quite fruity and has a slight sweetness to the taste which suggests a heavy dosage of the chenin blanc grape. Because of its slight residual sweetness, I prefer the Parducci as an aperitif rather than a wine to serve with food.

* N. V. Trefethen Eschol White Table Wine ($6.49). This might simply be the classiest of the white generic table wines on the market, but its price is high, reflecting the heavy percentage of chardonnay used in the blend. The wine is quite stylish with appley, crisp, moderately intense fruity flavors which are well balanced and never tiring to drink. It is an ideal wine for any Chesapeake Bay fish.

* 1980 Robert Mondavi White Table Wine ($3.59-$3.99). Mondavi's new vintage-dated white table wine is a big improvement over the recent non-vintage offerings from this winery. The bouquet is slightly herbaceous, which suggests that a high percentage of sauvignon blanc grapes was used in the final assemblage. However, the wine is quite dry, with a clean, medium-bodied, quite fruity feel in the mouth. The Red Jugs

* N. V. Diamond Oak Cellars ($3.99). This new winery has gotten limited play in East Coast markets, but its red table wine is one of the best values on the market. Medium ruby, with a bouquet and taste suggesting a blend of cabernet sauvignon and zinfandel. There is a good deal of stylish fruit to this wine to go along with its medium body. The impression created is one of a wine that is much more expensive than the price charged.

* N. V. Fetzer Premium Red Table Wine ($2.99). Fetzer's generic red table wines are consistently well made, and the new release, which is easily identified by a new label with a black and red border, is one of the winery's best generic wines to date. This medium-bodied, soft, spicy, fruity wine has a lovely, berry-like fruitiness and solid fruit.

* 1978 Inglenook Vintage Burgundy ($2.99). Every time I've had this wine I have been impressed with its burgundian earthiness and surprisingly complex bouquet for a wine of this price. I suspect, given the amazing amount of this wine made, there must be some bottle variation, but I have yet to discover it. At its best, this wine offers an amazingly spicy, fruity bouquet, with soft, lush, medium-bodied flavors and a degree of complexity that is unusual in wines in this price range. Be sure not to confuse this with the rather bland Inglenook non-vintage "Navalle" burgundy.

* 1978 Classic Dry Red Wine, Monterey Vineyard ($3.99-$4.29). One of the more intense red generic wines on the market, this big, pungent, spicy wine has a rather aggressive personality, and is probably best suited for drinking with your all-American hamburger or spareribs on July 4. It seems to have a bit more alcohol than some of its peers, but is well balanced in spite of its powerful and intense characteristics.

* 1979 Robert Mondavi Red Table Wine ($3.99). This wine is quite fresh, with a moderately intense berryish character reminiscent of a French beaujolais. It is soft, with attractive fruit, and when chilled is simply delightful to drink.