Yeah, so I finally caved in and paid the 30 bucks for a 12 month subscription of Xbox Live. I'm usually content playing single-player but I thought I'd give this multi-player thing a try for real. Here are my experiences so far.
 
Rainbow 6: Vegas
I've always enjoyed the Rainbow 6 series a lot but I've never tried it online before. I was surprised that not everyone was as super skilled as I had thought. First game I played I had around 8/15 KD ratio, even though my team lost. Compared to my god-awful Gears Of War stats when I tried playing that game online a while back (I had a free 1 month subscription) this was really good. I've done well enough in most matches to have fun. The game seems really balanced so I think I'll continue playing this one for some time. 

Super Street Fighter 2 Turbo HD Remix
I've always been awful at fighting games with the exception for Mortal Kombat 3, so it was no surprise when I got my ass handed to me in SSF2THDR. At least the game was nice enough to give me an achievement after 5 consecutive failures. I know playing with a gamepad isn't helping me much but I don't know if I'm willing to pay up for an arcade stick just yet. If you feel you're bad enough at fighting games and need another crappy opponent to play against, feel free to add me!
 
I'll write more later when I try some other games.

Three words: Modern Warfare 2 
 
Get it.

" Three words: Modern Warfare 2  Get it. "

Uno + Live Vision Camera = unique gaming experience. You will make loads of friends that way.

Well, thanks for the suggestions. Right now I'm not looking to buy any new games though. I already own enough games that haven't even been inside my Xbox yet, so I'm good.
 
Today I got kicked from an Attack & Defend game in R6:V when I captured the intel and we won the round. o_O I don't get it, isn't that what you're like supposed to do? Anyway, co-op T-hunt is probably my favourite mode so far, though it depends a lot on who you get teamed up with. So far I've been pretty lucky and played with decent players.