All time: Actraiser 2 on the SNES. I loved the first one, the combination of city-building and side-scrolling action was awesome. Then the second one came out, and they got rid of the city-building, which was 90% of what I like about the first game. Played about 3 hours of it, realized the city building was gone, and put it down, never to pick it up again.
This generation: FFXIII, Dead Island, Lair, Mafia II.
XI Wiki



