[Perndog]

I definitely agree with Ghosts N Goblins and Battletoads. Most people I've met don't even consider the 5 lives code for Battletoads to be cheating, and I can't imagine ever finishing it with two players.

I was going to say Contra was tough, but I managed to beat that (two players, but still a win) last summer. I always found Metroid, Kid Icarus, and Rad Racer to be difficult, but that might be because I was seven years old when I actually tried to get through them.