MadTV is a funny, and surprisingly long-lasting, sketch show. SNL is the king of the sketch shows and many other shows have tried to challenge SNL for the throne - all unsuccessfully. Although SNL remains the ratings and mind-share leader, MadTV has been able to carve out its own niche and thrive as the edgier #2 in the sketch comedy universe.
MadTV has been going for 14 seasons now. Very impressive.
Of the cast members on the show my personal favorites have been Bobby Lee and Keegan-Michael Key. Bobby Lee is just plain funny. He doesn't really even have to do anything. He's just funny standing still. Always a good trait in a comedian. Keegan is wittier and does more clever verbal bits.