The Adventure Time season one DVD set (26 episodes on two discs) came out a month ago, but we've been meaning to put in a plug for it. (Comic Con kind of derailed us, I guess.) There are two main reasons to pick this set up:
1) Even if you've already seen all of these episodes before, there's just something about watching like 10 or 15 episodes of this show in one sitting that is kind of magical. The cumulative insanity washes over you after a while, and you start to feel as though you really do live in the Land of Ooo. We watched a whole disc of this set, and a big part of the second, in one sitting — and afterwards, we gained a whole new appreciation for the friendship between Finn and Jake, not to mention the huge wealth of supporting characters in Adventure Time, from the various Princesses to Tree Trunks.
2) Despite being a relatively bare-bones two-disc set, this release does include some cute extras, including animatics with creators' commentary, and a couple of little compilations of silly cosplay and various Adventure Time events at conventions and stuff. But most of all, the set includes two utterly bizarre "making of" documentaries that pretty much deconstruct the notion of DVD featurettes. First, there's a featurette in which Pendelton Ward takes you around the studio where the show is filmed — which he helpfully points out is shot in one long continuous take, via a camera on his head. And it turns out that Finn, the star of the show, is real, and is a tiny cartoon terror who runs around the set causing havoc and hiding inside classic video games. And Finn has mind control powers if he crawls inside you. Okay, sure. The weirdness of this featurette — which I can't really do justice to with this description, you really have to watch it — is only outdone by the second featurette, which is a "making of" about the first "making of" featurette. And that's the one that gets really, gloriously bonkers. Let's just say there's some mo-cap action.
In any case, if you love Adventure Time as much as all right-thinking people, you should really pick up the season one set. It's much more nicely packaged than the earlier "random episodes shoved together" DVD, and it will fully increase your appreciation for the gonzo sensibility behind this show. Check it out!