Metroid prime 2: 35 hours( Lol, first prime game, I sucked XD)
Metroid prime: 18 hours
Metroid prime 3: 7 hours(I did it fast, but replayed it and did it like normal and that took 15 hours)
Zelda: The twilight princess: 40 hours and counting, probably 20 hours before I finish the game, so just take 60 hours. My very first zelda I played seriously.
Super mario galaxy: 40 hours, I collected all stars, so that means Luigi as well.
Super smash brawl: well not just singleplayer, but I've played it for 70 hours.