The first season is genuinely good. The plots are generally pretty simple and straight-forward an the comedy feels well put together. The writing takes a noticeable down-turn in the second and third seasons. The plots get looser and they feel like they always have to be saying something funny, and it just doesn't give the jokes enough room to breath. There are still a handful of good episodes in there, and I'm pretty sure that the "NO ANIMATION" gag, which is probably the hardest I laughed in the show's whole run, was from season 2 or 3.