Trials HD was a memorable one because I spent literally all day on the last extreme track and was elated when I finally finished it. Unfortunately it was after the patch that made it easier, so I can never brag about that.
Marvel 3, just because I'm not very good at fighting games and I loved this so I spent a good chunk of time learning how to play so I could actually be decent.
And 1 vs 100 because my friend is missing one achievement and he will never be able to get it.
@Laivasse: Analogue triggers are essential in Forza 3/4. If you spin out and try to get going again it's impossible to just slam down on the trigger and go because you'll just spin out again. You need to ease on the triggers and slowly build up speed.
@msavo: Yeah, Daniel's slow. His square attack is his sword, triangle is either a big hammer or bow and arrow depending on whether you hit down or up and circle he throws his head. I didn't really play him for much as I don't like slow characters, moved onto Jak who's got some speed.
I guess I'm being stupid but I can't work out the combo system. Square seems to be the light attack, triangle the heavy and circle the projectile, but I can't link any attacks into each other apart from square three times.
Although, playing as Daniel in arcade mode I managed to get Sweet Tooth in a pseudo-infinite by pressing down triangle, and then hitting up square and keeping him juggled in the air. Only worked once though, when I let him down I couldn't get him back to being stuck.
On the 3rd gen iPad and it's totally fucked. Every time I try to open it the game, zoom in or tap anything it closes itself. If I get past that and manage to start tapping it will reset itself after about 10 minutes and I lose all my coins.