For me I'd have to say Secret Of Mana, Donkey Kong Country, and any Mario Kart.

Mine is Super Mario Bros. 3. I replay it at least twice a year.

Signature says it all.

Jet Force Gemini.

F-Zero GX. Going on 2 years in May. Honestly the deepest action game I've touched. (Though I do love me some Melee and Advance Wars.) :3

Whatever the current Pokemon is - in fact, I've got a challenge out to beat X with every type once Bank hits.

Ocarina of time

I probably played through Sin & Punishment: Star Successor about 30 times since it came out.  I plan to play more.

Hard to narrow it down to one. Here's some games that I've played through many times and still am not sick of:

Original Legend of Zelda
Super Metroid
Resident Evil 4

I could also say Mega Man, Mega Man X and 2D Castlevania (PlayStation, GBA, DS) but there's not really ONE game that stands out from the rest in those series. Also, either SMB 3 or Super Mario World are kind of in that same catergory.

It's Dr. Mario for me. I unlocked it in WarioWare on my 3DS and it's gone up to the second most number of hours, 200+ for me, behind Animal Crossing (which gets playtime from my wife and me both).

I'm gonna go on a limb here and say Mystical Ninja Starring Goemon for the N64. They infused the Japanese atmosphere so much in that game, I can never get sick of it.

Zelda II. I have played and beaten it so many times already. On the first day of Summer vacation I would start a new file, then keep playing the file and see how many times I could beat the game. By the end of summer I was pretty quick with it too.

If you're talking single player it's NBA 2K13 on the Wii U.
Although I also love replaying
Lords of the Realm II and
Warcraft II



If you're talking multi-player you have to grab an older system
In multi-player mode I'll never tire of
Star Fox 64
Advance Wars
Battle Tanx Global Assault
Mario Kart Double Dash
Diddy Kong Racing

I beat Super Mario World 100% at least twice a year, every year, since 1992.  Yeah, that game never gets old.