ArmA has more then enough players. Unfortunately, many of them waste their time in ****ty custom maps playing deathmatch or team deathmatch
ArmA is only really fun when you play it with one or more guys on TS / Vent, imo. I've played pub by myself a few times but didn't like it at all. But when you use voice with a bunch of like-minded people, you're in for a great experience. So if you're interested in buying it, make sure you find a nice group to play it with (forums, clan, whatever). And if you're serious about ArmA multiplayer, then co-op is pretty much the only choice there is... but ArmA is at its best when played in co-op, so don't worry about that.
And to the guy above me, STALKER is a must-play. I doubt its multiplay is good, but STALKER is a singleplayer game anyway. That game is all about atmosphere and the experience of walking around in the Chernobyl area.
Usually I say: Let the people decide what's fun to them. But I find it both funny and extremely annoying how tactical multiplayer shooters get completely ruined by their communities (ArmA, GRAW2...).
Dogbadger, I'm not trying to be nasty, but ArmA will hurt your PC in a very, very bad way. Trust me I've played the game on a 6800GT machine with a slightly better CPU than yours, it was basically unplayable even at 'looks like arse' settings. The listed minimum specs for it are an absolute lie.
Add to this that it is far and away a worse game than OFP contextually, story and fun wise and it's easy for me to say stay away from it mate. It is honestly so ****ed up that you can't even get the AI to do simple things that they could do easily in OFP, which means making good missions is basically impossible. I am sorry I bought it, the only thing about it that is better than OFP is the online functionality (but even then as was said most servers are bull**** DM or TDM).
And to the guy above me, STALKER is a must-play. I doubt its multiplay is good, but STALKER is a singleplayer game anyway. That game is all about atmosphere and the experience of walking around in the Chernobyl area.
That being said, the recent Evolution Red map with the nuclear bombs is pretty fun to play, and the "defend the town from Alien spaceship invasion" looks to be silly fun.