Games that you play over and over and over....

[distortedreality]

Deus Ex is the big for me.....think i've replayed at least twice a year since release. Funnily enough I still manage to find new things most of the time

Chrono Trigger has been done to death as well, probably the most playthroughs of a single un-modded game i'll ever do. Can't ever see anything topping it.

Half Life 2 & Episodes - probably once a year (generally around E3 time lol) i'll do a run in the hope that i'm preparing for a quickly approaching Ep3 release

KoToR 1/2 - brilliant writing and gameplay. Best GTFO moment in gaming history.

Mass Effect 1/2 - same as above.

As for real old school games, I still crank out WinUAE once every few months and play through Wings, Beneath a Steel Sky, Cannon Fodder, Elite, Monkey Island 1/2, Megatraveller, Neuromancer, Syndicate etc.

 

[The Artificially Prolonged]

Mercenaries: Playground of Destruction, just loved going round and blowing stuff. Must of completed it upwards of 8 times.

Driver 2: Just loved driving round in Take A Ride mode creating amazing police chases.

 

[captain_dalan]

Master of Orion 1&2
Panzer General 1
Total War games-vanilla or modded
Jagged Alliance 2

Strategies offer most replay-ability

then:
Free Falcon
Mount&Blade
Baldur's Gate 1&2
Mass Effect 1&2

There are others, but these games are always installed in my PC and i play them at least once a year

why i play them? well, they are classics in genres i love playing, and are just plane fun even if you already all the ways to beat them

 

[GonzoGamer]

Monthly Rez playthrough oh yes oh yes.

That IS a game I keep going back to: Looking forward to Eden.
I usually dive back into old games over the summer. Besides Rez, I usually go back to San Andreas, Burnout Revenge (& 3), DoW Dark Crusade, and lately, I've been wanting to go back into Fallout 3 as a New Vegas palette cleanser.