Each season of South Park just gets better and better.
There's a couple of poorer episodes, like Britney's New Look, and EEK, A Penis, but the other episodes are the usual mix of mayhem, bad language, and giant Guinea Pigs that we've came to expect in this little Colorado town.
As for buying Blu-Ray over DVD, the only reason I bought the Blu-Ray was because it was cheaper than the DVD!?!? Go figure, huh?! But because it's an animation, you really dont get the same clarity as you get on a normal feature film.
Well worth buying, money well spent! :)