It's probably not the games, it's the people. I get online and either nobody is on or they're watching Netflix.
I remember the days when Halo 3 was THE game. Everyone had it and we would group up and play for hours. Now, however, I'm lucky if I even play anything with someone.
Online multiplayer is getting stale. Every game, it's pretty much the same shit. Go kill this, go capture that, etc, etc. Not to mention it seems like everyone worries about their K/D or W/L (mainly fighting games) and it really just kills the fun factor for me. I very rarely come across someone who plays for fun and has the same "fuck this shit, we're going for it" attitude I have.
Luckily, I'm fine with gaming in solitude. I've done it throughout a majority of my 20+ years of gaming.
As for game suggestions, maybe try something single-player, like Mass Effect or Castlevania SotN (XBLA).