How many ways are there to say that it's another slow Saturday night? That's one. It's even slower than last Saturday ,, night. That's two. Boy, is it slow on TV tonight. That's three . . .
* "Aliens for Breakfast" (8-9 p.m., Channel 2) -- Shelley Duvall is one of the executive producers of this special, which means one thing: quality family entertainment. And once again, she doesn't disappoint. Ben Savage stars as Richard, a young boy who hates his new sneakers but loves his new cereal: Alien Crisp. That's because when you add milk, the little alien in the bowl becomes alive -- played by Sinbad. Other players include Teri Garr and Alfre Woodard, and kids should eat this special up like -- well, like what we used to call Sugar Frosted Flakes. Clever premise, cleverly presented. ABC.
* "The Real Frankenstein: An Untold Story" (9-10 p.m., Channel 2) -- The Learning Channel already has done a fine "Great Books" special on Mary Shelley's classic novel and its inspirations -- but when David Frost gets hold of it, and presents Kenneth Branagh and Peter Boyle as featured guests, the result is a show with a lot more show biz and a lot more film clips, and that's a lot more accessible for younger viewers. ABC.
* "Saturday Night Live" (11:30 p.m.-1 a.m., Channel 11) -- This is called a "Sports Extra" edition of "SNL," because it culls sports-related skits featuring such guest hosts as Michael Jordan and Charles Barkley. Besides, it's a better title than "Another SNL Clip Show." NBC.
* "Super Dave's Vegas Extravaganza" (10:30-11 p.m., USA) -- Tonight's plot has Super Dave planning a Super Bowl spectacular of his own -- but in his case, a Super Bowl could mean nothing more than what he eats his cereal out of every morning.
* "Prehistoric Women" (1-3 a.m., TBS) -- Two fun bad movies are shown tonight on TBS: A 1967 film starring Martine Beswick as a prehistoric Queen . . .
* "Queen of Outer Space" (3-4:45 a.m., TBS) -- . . . and a 1958 film starring Zsa Zsa Gabor as an extraterrestrial one.