I'm not the kind of person who follows TV series, but this one is really incredible so I watched it every single day!!!
The show is extremely funny because all the actors (or at least those of the 2000-2001 season) are very talented and you can feel the pleasure they are having playing their character. They are/were almost all part of improvisation leagues so they are used to doing a lot of mimics, which is good for a comic show. Also the story is original in it's way of making fun of other shows like "Star Trek" and the references to music/cinema/sports are always well placed.
The episodes aren't equal in quality, but usually even the worst ones make you laugh at least twice or thrice. The way it is filmed also is pretty interesting: the camera moves a lot and always films in a weird angle.
Even if they say it was a show «made for children», everyone from 6 to 100 years old, should like it. An extraordinary show!