Online gamer, wanting a game that will last a long time.

So, the better ones for this profile are R2, FO3 and CoD:WaW, right?

Flow just get R2, most of us from warhawk are planning on playing it on a different night and you know you will want to play.

It depends on how you liked 4, if you loved it, then take WaW. Otherwise I would probably recommend R2, it is said to take several hundred hours to fully complete, with a long campaign a completely separate co-op mode, as well as 60 players online

I am choosing to get WaW over R2 personally, but that decision is affected by the fact I am pissed off at Sony for releasing R2 3 weeks later here, my friends have WaW and have been bugging me to get it, I don't like alien shooters as much as most (especially where there are horror elements) and I will be getting R2 later anyway

Fallout 3 is not online, but it can definitely last you a LONG time. If you're looking for something more non-linear and exploration-based, I would go with that.

I am egoistic and say Mirror's Edge (because I realy want a part 2). But from you list I enjoyed Fallout 3 the most and kept me also busy for a long time (Didn't played all of the games you listed though).