Shadow blind - if your a fan of SOCOM and you want a blu-tooth head set then SOCOM first is a good desicion. (official Ps3 headset in socom > Jabra headset in warhawk)

I went to Walmart and Target today (Christmas shopping). They had the Warhawk bundle for $20 and $30, respectively. If you're going to get SOCOM, then get the bundle. The headset is way better.

It's actually very good. People just don't like it because it's not PSN, so they have to log in separately.

EDIT: You like stealth games? MGS4 is the best stealth game this gen. The online is very good as long as you don't mind a different login, and the single player is excellent.

I know you're set on Sigma, but I warn you now: it's not good. The graphics are last-gen, the gameplay is repetitive and the difficulty is ridiculous. You'd be better off with DMC4 or, if you have a lot of patience, God of War III.

As far as online goes I'd say:

1. Socom: Seems to be a love it-hate it affair, If you're looking for a great online experience, this is a great place to look. There's a large following of people out there that really LOVE this game for good reason. Bundle comes with the official headset if you don't have one yet which alot better than the warhawk bundle.

2. Resistance 2 (co-op): The co op mode is very unique and you could put lots and lots of time into it if you wanted to. Competitive multiplayer is alot of more of the same Halo-esc deathmatch.

3. CallOfDuty (4 or Waw) This game fell down the ladder for me largely cause i played 4 a whole lot last year, and Waw was too similar, Has a lot to upgrade, but seems to lack some of the replayability the first two on my list have.

4. Warhawk: Good game with solid graphics and gameplay - it's really 'a lovechild between unreal tournament and battlefield' but third person. Not too expensive of a game either.

There's alot of games out there like little big planet that have online modes, but not as much of an 'online focus' like the games i listed above.

MGO: A real hassle to get started, really seems to me to be a good game to people that love Metal gear, but if you don't you won't think much of it. This is kind of a free bonus you get for buying metal gear solid 4 - I'd buy this game for the single player first.

 I've played and beaten every Ninja Gaiden game, from the Xbox original to NGBlack to NG2. The difficulty doesn't bother me anymore. The screenshots of the graphics that I've seen make it look like a pretty good PS3 game, alot better then many out there. I haven't seen it in action though. Looks better then DMC4 to me (which I've already played 360 version of)

As for MGS4, I'll probably just end up borrowing it from my friend. It just doesn't look fun to me.

Believe me, I've known plenty of people who doubted it, but I don't know a single person who has played it who doesn't like it. It is amazing. Just have a look at IGN's story so far, and you'll be good to go.

I suppose Ninja Gaiden Sigma could be a love-hate thing. I'm on the hate side.

isn'y sigma just a remake of black?

Yeah. But its pretty cheap now, and there are lots of extra stuff added in. That, combined with the fact that its also (by review standards) one of PS3s best games and I'm a massive Ninja Gaiden and God of War(If games could be brothers, they would be) fan, im sold :P

@Kantor: I know what your saying, and I'll definately check it out at least down the road. The thought of 40 minute cut-scenes NOT from a JRPG though scares me. 

warhawk is awesome(buyits only 30 bucks),even though you may not be interested in it.You should try R2,its worth at least a 6 dollar rental(i would buy it however).Uncharted is a great SP experience. other than that.wait for KZ2.

A good example of this is OkeyDokey. He beat MGS (I think), but could never make it through MGS 2 or 3.  He tried MGS4 on a whim, and it shot straight up to his favorite ps3 game.