Re: top 5 alltime sitcoms
you guys listed off some good ones, just two i would add to the list:
welcome back kotter: great show about a class of misfits/losers taught by a former member of that same class. unfortunately it only lasted four seasons. john travolta got one of his first gigs on that show.
freaks and geeks: great one season show about two social groups in the 1980s (hmm... can you guess which ones?). some good storylines and good one liners. it troubles me that the guidance counselor from the show is now that naked trucker on that show on comedy central.
otherwise i like seinfeld, fresh prince, the tgif shows from the 1990s and the wonder years. i respect others that have been mentioned but they aren't really my favorites.