Great choices @wiseagent
Donkey Kong is a classic, that's for sure. I used to play it on the Sinclair Spectrum. Lots of fun but super hard.
Mortal Kombat on the Sega Megadrive was kick ass good. My younger brother was very good at it. I still love Street Fighter 2 as the best fighting game though.
I remember completing the original Resident Evil on the PS1. It was very jumpy and had my on edge constantly. If you enjoy creepy games the I can recommend Outlast. I was absolutely bricking it all the way through until I completed it.
Good luck with the contest.