Zelda franchise deserves its own topic when it comes to Nintendo platform games. Of Zelda games specifically, I'll probably go with Ocarina of Time for it being the first one to be made in 3D, have memorable gameplay and story while just being awesome. Even though I love Saria's song, Gerudo Valley and other tracks within OoT, I must concede that with regards to OST that A Link to the Past(Dark World is the best track of all time) and Wind Waker's OST are just better. Wind Waker in particular, even though its artsy style made it unappealing(and it got knocked for that) had an open world feel that was repeated on future titles. Even though I've never played Wind Waker, from what I've seen of the game I'd probably rate it as my #2 Zelda title behind OoT. In order: OoT, WW, ALttP, Majora's Mask and Original Zelda(love for the classics).
For Non-Zelda, I'm going back to my old school roots and the original Super Mario World. I remember playing the original Super Mario Brothers with the iconic soundtrack but SMW was the first game I played religiously as a 5/6 year old. Super Smash Brothers is a close second.