Funny show, memorable characters and episodes, lots of funny and insane ideas executed wonderfully, along with interesting commentary on current events, or events of its time, and still having fun episodes just following the boys at school or silly things too. It's a good mix. Not only is it hilarious and clever, but it also has some good messages and nice moments too.
Best seasons are 5-10 I'd say. Seasons 1-3 were different and more stupid and lighthearted, edgy for it's time but not much so anymore. Season 4 seemed kinda experimental. Still charming though. Every season has its own charm. Hilarious show, tons of funny moments that will stick in your head, or just good stories. Cartman and Kyle's rivalry is funny to see, and seeing Cartman and Butters paired up makes some of the funniest episodes. Even in the less good seasons, there's still hilarious episodes and moments, there's never a bad season.