There are plenty of gaming references (and even entire episodes) in Adventure Time - there's even a video game system as a character - but really, I've always felt the most video gamey episode of all is actually one that doesn't even directly involve them.
I'm talking about The Enchiridion, from the show's first series. Pitched as a quest, from start to end it's so segmented and absurd that it feels like the greatest video game never made.
I'm obviously not alone in thinking that, because the collector's edition of the upcoming DS and 3DS game Adventure Time: Hey Ice King! Why'd You Steal Our Garbage? comes in a steelbook case made to look like the exhalted tome. It also comes with a map of Ooo, a sword stylus and a bestiary. All for an extra $10.