It's funny to see the variances in opinions as to what's "timeless" and what isn't. It would be interesting if everyone put in their ages as well.
Many of the games called out as "timeless" are nothing to me in this list, as I'm sure many of mine are to others. As I said, I wonder if the generation you come into video games with has anything to do with your appreciation. Here are mine:
NES:
Zelda 1
Mario 1
Mario 2
Bionic Commando
Castlevania 1 & 3
Baseball Stars
Tecmo Super Bowl
Contra (and Super Contra)
Metroid
Final Fantasy
The Ikari Warriors Code (A-B-B-A)
Ok, Gradius as well
SEGA MASTER SYSTEM:
Space Harrier
Wonder Boy 2&3
Great Baseball
Ghost House
Really all of their sports games had that "Special" Sega touch
GENESIS:
Mutant League Football
Mutant League Hockey
Zombies Ate My Neighbors
Lost Vikings
SNES:
Final Fantasy II
Final Fantasy III
Super Metroid
Tetris Attack
Metal Warriors
Lost Vikings II
PLAYSTATION:
Castlevania: Symphony of the Night
Parappa the Rappa
Intelligent Qube
PC:
Civilization
King's Quest (the ones where you type commands)
Doom
Scorched Earth (Worms' little-known grandfather)
GETS A SPECIAL NOD:
Halo
Pikmin
Street Fighter II
Mortal Kombat
Don't get all flame-crazy on me for this statement because I'm not trying to push this on you, but I would honestly rather play ANY of these games than 99.9% of games out on other consoles today. Maybe it's just the nostalgia, but something about today's games just falls flat on me.
Even Gamecube games (Yes, I could probably be called a Nintendo fanboy), though great, are longer on effects and shorter on "fun" than old-school Nintendo. LONG LIVE TECMO SUPER BOWL!