After 100 years, the Ringling Bros. and Barnum & Bailey Circus is still calling itself the greatest show on earth. Or as Ringmaster Jim Ragano puts it in his stentorian Mister Showbiz voice: the GREATest SHOW on EARTH!

We'll let Prince and "Cats" and Wayne Newton fight over that title.

But at nearly three non-stop, head- "swiveling, eye-rolling, ear-filling hours of parades, animals, rhinestones, ooom-pah- pah, contortionists, clowns and colored lights, the circus is indisputably still the greatest bargain on earth.

You can run off and join the circus at the D.C. Armory every day through April 15, with matinees most days. Tickets are $6, $7.50 and $9.50, and are available at the Armory, at Ticketron, or by calling 543- 5646. The Orange and Blue Metro lines will let you out right at the place. Call 546-7470 for performance times, which vary from day to day.

Kids, even the most video-addicted, will be enchanted. In fact, the three-year-old sitting in front of us, a sort of three-ring annex in himself, was so mesmerized that he did a tumbling act up and down the aisles, and clapped his hands over his mouth in genuine awe when Captain Christopher was shot out of the giant rocket. There go his parents' high hopes for his career as a doctor or lawyer or something.

Even if you're thirty times three, you will be thrilled by the tigers and the truly scary aerial stuff. And though it's impossible to see it all on one visit, it's not as noisy, smelly and overwhelming as the circus in your memory probably is.

Betcha Didn't Know Dep't:

* There are 21 female elephants in the "cast" (male elephants are cranky and not as easily trained). The circus' animal kingdom also includes a dozen rare white tigers (no wimpy zoo tigers these); plus balancing Bulgarian bears, hoop-jumping zebras, camels and horses. And you just can't afford to miss Miss Antoaneta's unforgettable act which features pigeons 'n' poodles -- together at last!

* The circus really is a family affair: Among the 125 performers and 125 crew members, there are at least eight families, including the Gautiers, who work the elephants; two death-defying trapeze families, the Flying Ramons and the Flying Vasquez (including Miguel Vasquez, the only man in history to do the breathtaking quadruple somersault -- he didn't make it the night we were there); the Rodogels, who do somersaults on stilts; the Duo Kristov, above-it-all aerialists; the balancing Alexi Brothers; and the equestrian Romanovis, who build human pyramids on horseback and other foolhardy stuff.

* There's a guy named Charlie Brown (no fooling) who sits in the basement at the Armory popping that famous circus popcorn all day -- there are boxes of it stacked up to the ceiling.

You can also buy (and will, if the determined and endlessly entertaining vendors have their way): red and blue revolving circus flashlights, inflatable gorillas and countless other plastic and fuzzy memorabilia; sno-cones in colors not found in nature; and of course, sticky, icky cotton candy in blue, pink and purple.

And the clowns, all 25 of them, really are funny (no kidding).