Yes, I stole this thread idea by misreading the title of another thread :P

Anyway, for me it could be any of Civilisation on the hardest difficulty setting, Mega Man 9, or Age of Empires 2 against some friends who are very good...

man I suck :P

F-ZERO GX Story Mode. It seperates the men from the Gods.

Good answer, I didn't end up completing story mode on the hardest difficulty

I'd say Gradius III is one of those games you play and makes you realize you suck. Not because it's hard, but mostly because you die of cheap deaths! Konami tried to make money in the arcades with this game! D:

Mario Lost Levels- when I got it on Mario All Stars for SNES

Ninja Gaiden on the NES.

Super Mario Land was probably the first game I ever played that I thought "This is REALLY hard."

What? You thought it was hard? ;)

For me it might have been Empire Strikes Back on the SNES, Jedi mode, i beat it in the end but by god it was hard.  I doubt i'd have the skills for a game like that these days.

Super Ghouls and Goblins for the SNES, try to complete the game on normal (if you can), and then try to do it again on professional mode XD i bet you'll lose all your lives in just the first seconds of the game :P

lol me to I never made it past the first level :S