Not going to suggest a game, but I am going to say that I can't get into any MMOs or even top selling FPS games unless I have a close group of regular people to play with. It doesn't matter how good the game is, if there's no regular troupe, there's no game IMO. Perhaps this is the root of your funk?
I've often found that the sheer volume of people playing games in TOG can work against this (Bad Company 2, for example). Every time I log on there are 30 new names or voices to learn and everyone tends to turn into just random faces in a vast sea. While this can be fun if the division is really large then the community aspects tend to feel distant and vacant. The natural side effect of this is that smaller groups tend to form out of the masses.
If you really want to get into a game for the long haul I think you need to find a small group that always play at the same time as you and has the same gaming tastes. The best way I've found to do this is to take a risk on a new game you think you'll really enjoy, get in with the early crowd. Use the public or division forums to organise US game sessions on Teamspeak/Ventrilo/Mumble voice ect (unless someone is already organising them) and things just kind of roll on from there. If you don't have a microphone/headset, get one yesterday.
I think with multiplayer games the people you play with matter a lot more than the game you play. There are already quite a few sub-groups of people in TOG who kind of follow each other around from game to game as new titles are released, and each of them often use different voice servers to the ones the standard TOG division promotes - mostly out of habit and because those people might play several different games in a night and thus don't want to keep changing voice channels/servers. Getting in early is probably the best way to find or forge these sub-groups as one of the best things about gaming is exploring new games, and there's nothing better than exploring new multiplayer games with a group of people you've played with a lot previously.
Of course, exploring new games risks your hard earned $$$ and it's not always a solid bet, but it's damn fun and often worth the risks.