Er... I kinda disagree on "Contra." Own it since childhood and you really don't find it that hard. I agree with Strong Beef: when you've played the game your whole life, you've learned it enough that nothing can challenge you. I can finish it in under 15 minutes without significantly losing any lives. Certainly without the 30-lives Konami code.

Now I also agree with Satchmo: "Ghosts n' Goblins" should DEFINITELY be on that list. It was my impression that everybody agreed this was the hardest game of all time! Not only it was impossible to beat, but it was also impossible to CARE about beating it! It was such an unwelcoming game, with the worst play-control I've ever experienced.

Now, "Castlevania III" was also a very hard game. Dracula was never so hard as he was in that game.