Maybe....

Super Mario World, Super Mario 3 are timeless classics.

Chrono Trigger, Secret of Mana, FF IV, FF VI and FF VII (for me at least) are RPGs I will always want to come back to.

Starcraft is the ultimate RTS and can't be touched (which makes me sad because I can't help but think Starcraft II won't hold up to the original).

Diablo II also doesn't get old no matter how many Amazons I make.

I play newer RTS games, but I always go back to Starcraft.

MGS2-4 will never get old
RE4 will never get old.
Disgaea Series never gets old.

Can't agree with Halo:Combat Evolved and GTA III (GTA 2 - yes)

I cant count 3 and 4 to get old since its not been so long since they were released..

RE4 did get old in 2 playtrough.

Disgaea Series,havent played but seems that they don't.

List is only what I have played and as I said I will add sometimes new stuff there.

No way man...RE4 i've beaten on 3 different consoles multiple times. Even now that I play Dead Space, I am reminded howmuch better RE4 was... Truly one of the best games ever made.

I agree with most of the "get old" list except for MGS and GTAIII. I beat them recently (this year) and both have aged very well, specially MGS

Also agree with the "don't get old" list, and some additions:
Suikoden II (being 2D has done wonders to the non-aging of this game)
Chrono Cross (still as excellent as ever)
Disgaea (As graphics were never the strength of this game, it doesn't age)
Chrono Trigger
Final Fantasy VIII (it doesn't look as bad as FFVII, and the amazing battle system is still intact)

Oh so true. I didn't include it in my list because I thought it wasn't old enough yet.

@zexen : Chrono Cross always sucked and always will.

@TruckOSaurus:
Chrono Cross sucks?! C'mon that is just not true!
What exactly sucks in the game? Great battle system, awsome graphics, excellent music, character are a little shallow I'll admit, but the story, inspite being poorly told, it's still a good story...
I'm not saying that the game compares to the AWSOMENESS that is Chrono Trigger, but "the game sucked and always will"?