chrono trigger, possibly the only squaresoft game that didnt feel repeteive playing through it multiple times, (cu zthere were so many different ways you could do things, i know i got at least 6 different endings) beating lavos with just chrono and marle got you that ending where you talk to the "staff" of the game as npcs, then marle and crono floated into the sky on balloons,
however, since everyone is gponna pick that i hafta go a different way, goldeneye for the n64 had to be one of my favorites, its multiplayer was the most fun thing ever, multiplayer fps's never reached that level of fun until halo came out (thats a huge time gap) , and even then that didnt last long, im waiting for halo 2, maybe they didnt screw the multiplayer up,
though if i wanna go really really far back i remeber playing duck hunt until my NES froze everytime, oi loved that game, and it turned me into the sharpshooter i am today,