What was everyone's game of the year to play stoned? Its a tossup of Warioware and Mario Party Superstars. Psychonauts 2 was fun too.
Those 2 would be my runners up. Although I'd probably go with Mario Party Superstars. Wario Ware can require too much focus at times. With Mario Party Superstars you only need to focus hard during the minigames and you can chill out a bit during the board segments. Perfect balance.
Psychonauts was a game I thought I'd enjoy high, but mostly didn't end up that way. The trippy visuals are great, especially psi king's level, but the gameplay isn't interesting enough to hold my stoned attention. And I have trouble following game stories when I'm stoned. Movies I can follow, but with games, by the time I get from one cutscene to the next I'm often like "wait, what was going on"?
Best game? Curb Your Enthusiasm. It is fucking amazing when you're high. I don't care that it's not a game. Still my top choice. If you don't like it, tough shit.