Some most enjoying games I've played...

NES                          NOTES

Battle Of Olympus	     Rather difficult, but nice adventurer
with cool music.
Blaster Master               
Castlevania 2: Simons Quest  Superb.
Cobra Triangle		     One of the most difficult games on NES,
still fun though. :)
Duck Tales 1&2               
Faxanadu                     One of the very best. Really memorable.
Megaman 1-4		     These are just so fun to play. Awesome
soundtracks.(Except MM1:)
Metal Gear 1                 
Metroid
Ninja Gaiden 1-3	     Excellent trilogy with awesome
soundtrack in each of them.
Nintendo World Cup           Best two player soccer game there was. :)
RiverCity Ransom
Rygar                        Cool as hell, that whip really ownz.
Solomons Key                 Best puzzle there is on nes.
Solar Jetman                 My first nes game besides smb1... :)
Super Mario Bros 1-3+LW      
Swords & Serpents
Turtles 1
Werewolf
W&W 2: Iron Sword	     Just cool with some exceptional great
music.
Zelda 1&2

SNES

ActRaiser
Chrono Trigger               Second best music in gaming history.
Final Fantasy 6 	     Truly awesome soundtrack, best in any
game I've ever seen.
Secret Of Mana (SD2)         Best two-player RPG I've played.
Secret Of Mana 2 (SD3)       
Super Metroid
Tales Of Phantasia

PC

Alien vs. Predator 2
Deus Ex                      Really intelligent with awesome plot.
Elasto Mania
GTA3
GTA: Vice City
Mafia                        Truly Fantastic.
Need For Speed: Hot Pursuit 2
Red Alert 2                  
Resident Evil 1-3
Silent Hill 1-3
Virtual Pool 3


PSX

Final Fantasy 7             Most memorable game I've played.
Legend Of Dragoon
Metal Gear Solid
Project Overkill            Fun with two players.