If you had to play a game forever...

[DrunkenKitty]

EVE Online

Same. The only thing that could be infinitely varied enough to be interesting forever is social interaction.

 

[Phoenix Arrow]

Silent Hill 3 probably. If I was feeling sensible then I'd pick TF2 or FFXI.

 

[Joe.]

MGO off of MGS4. I don't know how Konami did it but the online is addicting for me.

 

[Lusperus]

Mario kart or
SSBB

 

[Shepard's Shadow]

Star Wars The Old Republic. Okay, it hasnt been released yet; but, if it looks and plays as good as the trailer at E3 looked, then i could play it forever w/ out getting bored. But a game thats currently out....Morrowind. I would have said Oblivion but their are like 10 va's used and the level scaling is ridiculous. I spend most of my time being invisible.

 

[DrJonAngus]

I would have to say Earthbound or Chrono Trigger for the SNES or quite possibly Shin Megami Tensei Nocturne. Overall, a pretty decent RPG would suffice.

 

[6PrinceofDarkness6]

Artificial Girl 3 with all the mods installed.

+1 Internets.

I'd go for Front Mission 3. Keep me brains' intact.