NES was AWESOME. my first system and the thing that is solely responsible for my love of video games.
the games i loved most:
contra
double dragon 1/2 (2 was better)
dragon warrior
legend of zelda
megaman 2
castlevania 2
turtles 2
punch out
ninja gaiden
mario 1-3
of those, the only ones i could actually beat were the double dragon games, dragon warrior, turtles 2, and contra (with code)
as a bonus:
best genesis games:
1. gunstar heroes - to this day the best sidescrolling action game
2. mutant league football - to this day the best sports game
3. streets of rage 1-2 - to this day the best beat-em-ups (except maybe that D&D arcade game)
4. road rash 2 - to this day the best racing game
5. flashback
plus: zombies ate my neighbors, lost vikings, mortal kombat 1-2, Street fighter 2
i beat all the genesis games on this list except lost vikings, zombies, and flashback. I still complete gunstar heroes and streets of rage about twice a year.