We forget how many times amnesia's been used as a gimmick on TV shows (Dallas, anyone?), but it doesn't mean it can't work. And in Samantha Who?, currently showing its second season on YES Stars Comedy, it works well, judging from the series's first episode I caught recently on the Net in a bid to catch up on what I've missed on YES. Samantha Newly (Christina Applegate, best know for her role in Married With Children), is introduced to us in a coma, but it's not all bad, as she tells us in one of a series of voice-overs that run throughout the fast-moving program. "No fattening food, lots of rest, and sponge baths every day," she notes cheerfully. The down side: "Nose itch, that Pina Colada song stuck in my head, and oh yeah, sometimes I can hear what people in my room are saying." Unfortunately, that also includes her boisterous mother Regina, played by the incredible as always Jean Smart (Designing Women), who's capturing her daughter's tragedy for Extreme Makeover: Home Edition. And also along for the fun is Kevin Dunn as Samantha's dad Howard, almost as clueless as he was in the Transformers movies. It seems poor Samantha was the victim of a hit-and-run driver eight days earlier, leaving her with "retrograde amnesia," a scientific term for not being able to remember almost a blessed thing. Not who your parents, friends, or lovers are. What you like to eat. Almost nada. Finally out of the hospital she is desperately trying to piece together her life, with the various parts introduced on little blackboards bearing messages like: "My Boyfriend" or "My Best Friend." It is all very messy thanks to friend Andrea (the outrageous Jennifer Esposito of Spin City), who knows more about Samantha's peccadilloes than anyone, but is only giving information out on a need to know basis. The writing's great, as when Regina and Andrea -- who's a bit of a lush -- face off at Samantha's parents' house, where Regina suggests "you might want to switch drinking arms. Don't want to build up too much on one side." When poor Samantha, despearate for some knowledge, pleads with her mother: "You made me what I am!" Regina snaps back; "That's a terrible thing to say." "Apologize to your mother young lady," adds dad. The more she discovers, the more complicated her life is. There's a sort of boyfriend named Todd who she met when she stole his latte, and a mysterious character named Rene, who not only wants to whisk Samantha off to Hawaii, but is also, Andrea adds in passing, married. Through it all, Applegate makes her character as much fun as the rest of the crew, proving she has the star quality many predicted for her on Married With Children. Todd tries to be helpful: "You love Elvis Costello, you hate opera, and you take Gummy Bear vitamins because you can't swallow pills," he offers when she briefly moves in with him after fleeing her parents' place. That comes in handy when Rene -- whom she initially thought was a woman friend of hers -- grabs her for a kiss as she walks into his party, the dazed Samantha, with Applegate at her best, only able to respond: "I...can't...swallow...pills." So home she goes -- back to crazy mom and dad, with Regina greeting her at the door. "Before I come in, just tell me you're not the one who tried to run me down," asks Samantha of her mom, who's too busy telling Howard her baby's back home and getting her old room ready. "Just one more," asks Samantha, crossing her fingers as she crosses the threshhold: "Is there any chance I was adopted?" Will Samantha figure it all out? What other skeletons are in her closet? It's all great fun, and Smart practically steals the show with her over the top-performance. Applegate's crisp, the pace is fine, and the music -- including "The Pina Colada Song" (actually called "Escape") as the credits roll along -- is also fun. So why did Samantha Who? die after two seasons while According to Jim and other lesser comedies rolled on and on? Go figure. Meanwhile, enjoy season two while you can, catch season one on the Web, and remember: amnesia's never having to be responsible for what happened to the remote. Samantha Who? airs weeknights on YES Stars Comedy at 7:30 p.m.