I haven't spent a lot of time with Season 3 unfortunately so I don't have much of an opinion on that. As far as Season 1 and 2 (my favorite season) go...
Season 1: Situation: Comedy. While I found a lot of the jokes funny ("Nah, I don't watch horror movies." "Die! Why won't you die!") and the introduction of Hugh Bliss *ding* always freaks my friends out, the puzzles weren't particularly clever. Culture Shock wasn't bad for the first episode, plus I enjoyed it my first time through otherwise that would be on here as well. I liked the C.O.P.S. a lot and thought they were hilarious! But some parts of Reality 2.0 were annoying, the text-based portion was genius though!
Season 2: Maoi Better Blues. Again, I liked the comedy. Max freaking out over Baby Jimmy Hoffa was painfully adorable, but the overall 'plot' of the episode and the puzzles were very shallow and pretty lame compared to the rest in the season.