ok i know i did my faves but after reading more there are some forgotten titles which deserve mention.
Blaster Master on NES - still impresses me to this day. A/V perfection, metroid fun gameplay, they were on crack when they made this. why does this game not get the respect it deserves? the true hardcores never do.
mega man 1+2 are still tons of fun. so is SMB 1, Zelda 1, life force, contra. Ok so I'm a bit of a NES head, and eveyrone knows these games.. but still. They're just the best of the best!
on Genesis, we had the Shinobi series, sonic (I don't remember 3 so well), thunderforce and musha. SNES had spaaaaaaaace megaforce (presented by toho).
And PCE had galaga '90 which is a perfect portable game..