Mine would be Skies of Arcadia and, Banjo Kazooie/Tooie and Legend of Zelda Ocarina of Time/Majoras Mask
Skies of Arcadia is less a game I played ritually as a kid and more one I once dreamed of playing. When I was a kid (6-8 years old) a friend of mine used to play the original SoA and I would usually watch and play the occasional level. Thing was at the time I had an N64 not a Dreamcast so I didn?t have my own copy to play it properly. Eventually after a few years I found the game had been rereleased on the Gamecube and I decide now was the time to finally play the game for real and I was dumbstruck! It seriously is one of my all-time favourite games but weirdly very few people actually seem to remember it or have ever played it. It ranks somewhere alongside ?Primal? as a game that is a blend of Western/Japanese creation that very few people seem to have heard of. Back when I first heard about it I paid about £15 for a copy on the Gamecube, I just checked now and the price has gone up to a minimum of around £40!
Banjo Kazooie and Legend of Zelda were one of the first games I had ever played and were on the N64 back when it was new. They were the games I would run home to play and me and my friends would discuss strategies, hidden finds etc.
Even on new reboots on XBLA and Gamecube they still take me back to those times when I first picked up the controller and inherited the title of Gamer. These are the old games I replay every few years to remind myself what true gaming is all about, not achievements or blasting noobs, but epic ship battles with pirates, fighting giant Balloon Dinosaurs and charging around the land on horseback to save a kingdom.