What is a very long lasting computer game?

I am very bored and I want to play a computer game. The genre doesn't necessarily matter but I want it be loooooooong.What is a very long lasting computer game?
a cool game i play alot is

install windows
World of Warcraft is a massive time-sync. Of course they charge monthly, but the social-networking aspect and fun of the game makes it totally worth the monthly cost of $15 and the initial cost of the game is relatively cheap, enjoyment is great.



I played it for 2.5 years and stopped because of work, but it's a "very long-lasting" game that doesn't really get old.What is a very long lasting computer game?
In terms of turn-based strategy - X-Com: Terror From the Deep. (Just recently added to the Steam lineup for $5!!)



RTS - Warcraft II comes to mind.



RPG - Lots of single-player RPG's out there that don't require much to run them, with few exceptions. Checkout Planescape: Torment, FF VII if you've never played it, Diablo II (don't bother too much with the first one). Dungeon Siege isn't horrible, either.



FPS - The original Unreal Tournament is a classic. You can probably score Quake 3: Team Arena, too. These two games require about the same spec's as HL 1. And if you've never played CS (Counter Strike). You won't be able to play CS:S most likely, but you can play CS if you can play HL 1. Also, if you have a slow inet connection or don't like getting pwned on CS, try CS: Condition Zero. It's a single player version of CS.
Fallout 3 (easily put 50 hours into this ame, more than likely 75-150 hours with down-loadable contents)



Counter Strike: Source



Sims (2 or 3)



Gta 4 (although this requires a very high spec pc to be able to run even on low settings)



Dragon Age Origins



Call of Duty: Modern Warfare (or/and modern warfare 2)What is a very long lasting computer game?
World of warcraft.



Many of the first 4million to buy the game back in 2004 are still playing now were closing 12million players soon



All from a game that came out back in 2004. Now that's stay power!!!!
the sims 3