Red Five said:
Beating Ninja Gaiden. I did it on the NES online version with save states and it was still the hardest thing I've done.
A lot of the NES games are ridiculously hard, even with cheats.
I did land on the aircraft carrier on the first try on Top Gun.
Mario 64 wasn't that hard but it is a fun game. Might have to get my 64 out and play it again.