Metal Gear Solid 3. I played it when I was reasonably young, and I didn't have a single clue about the story line or any idea how to do the mission(s). I hope I'm not the only one, lol.
Without cheating and looking up the methods to beating the game which is what I did, I would say end on end that Portal was a pretty hard game to beat, probably the hardest game I've ever played.
dark secotor for the 360 i dont understand it
Mine was the Lost Game it was hard as hell to complete but i got there it took a few weeks tho.
I would have to say it would be the GOD OF WAR PACK I II III.
going to have to say portal idk why but that game was wicked hard for me to complete
I can't remember any hardest game.
GOW on Insane. It is fukcing Insane.
for me probably Daxter, for the psp, I can't remember what level it was, I'm sure its possible, but I have never seen anyone beat it.
I would say demon souls on the hardest difficulty.