Sitcoms have been struggling since Frasier, Friends, and Seinfeld signed off the air during the course of the last decade, and canned laughter has lost its appeal for many viewers.

While The Big Bang Theory (CBS) does offer some fresh one-liners - like "We've already watched Battlestar Galactica Season Two" and "Not with commentary!" - it plays on expected stereotypes, in this case, two socially challenged brainiacs who become intertwined with their new neighbor, a slightly ditzy server at the Cheesecake Factory. While romantic promise is there, you're just waiting for the pocket-protector jokes to surface.

Back to You (Fox) is equally mediocre. Anchorman Kelsey Grammer gets demoted and transferred back to his old Colorado station after freaking out at a coworker while on the air in Los Angeles, and his old coanchor (Patricia Heaton) has a grudge against him. Some peppy one-liners are marred by a lack of real chemistry between the stars. There is a big revelation in the pilot that may keep viewers watching, but for how long is yet to be seen.

Samantha Who? (ABC) is undoubtedly the best new comedy of the season, and it needs no laugh track. Christina Applegate plays an amnesia victim who can't remember that she was a shallow, unfaithful club girl with vapid family and friends. Shocked at her former life, Sam quickly decides that her new blank slate of a life has advantages, one of them being that she can change who she was. And in this role, the endearing Applegate can continue to buck her old Kelly Bundy image.