MGS: Peace Walker.
Clocked 40 hours so far and I still havent built my Metal Gear Zeke yet. Much much better on the PS3 than on the PSP with only one analogue stick. Only problem is it gets quite repetitive having to replay endless mech, tank, helicopter battles etc and without replaying certain extra ops over and over its also hard to level up your various staff teams. Probably be much easier and fadter playing co-op I suppose.
Anyway once ive done it once, I dont think ill do it again. Just selecting the story missions and breezing through those with all my new gear shouldnt take any longer than the other MGS games next time I play.