Are there any games you come back to and play over again every once in a while?
FF1 was this for me for a long time. Between new games, I'd pop in FF1 and try a new party. Then I ended up making the site, and then all the remakes, so I've ended up playing it quite a bit.
Super Mario Bros. is nice to throw in and see how fast I can beat it. With warps I can do it in 5 minutes or so.
I guess SMB3 is another one. My niece and I decided to play it today without warps. Playing with her, by the way, is a different experience. I have to beat most of the harder levels, and as a result, I get almost none of the items.
I always replay ActRaiser, Silent Hill, Super Metroid, and Day of the Tentacle every so often. I have a feeling I'll be playing Shadow of the Colossus regularly as well.
Games I've often replayed every and then include:
-Super Mario Bros. (NES). I've never been able to beat it, though. ^^;
-Super Mario Bros. 3 (NES). This one I have beaten on numerous occasions. Still remains one of my favorites from my childhood.
-Legend of Zelda (NES, along with the Classic NES series version for the GBA). I've only beaten the first quest, though. ^^;
-Final Fantasy, specifically the PSX and GBA versions.
-the first 3 Spyro games (PSX).
I recently finished playing the DS version of Chrono Trigger, and I've got a good feeling that I'll be replaying it again. ^_^
My nostalgia goes a little bit later than most of yours.
I still do this with Fire Emblem 7, Legend of Zelda: Wind Waker, and Paper Mario: The Thousand Year Door.
If I had only three games to play for the rest of my life, excluding stuff with downloadable content, those would be the three. Nostalgia does not die.