Casual/Lobby PVE Game?

I've been extremely wishy-washy/indecisive/ADD over games for the last 2 years or so now. I've played WoW since early 2005 (and still maintain a sub), but it's lost its appeal since Cataclysm.

I've played almost all of the major MMOs there are, and now I'm feeling lost. These days, I don't have the hours upon hours I had during college to spend playing a game, so I'm looking for something a little more bite-sized, yet still maintaining a rewarding experience. I feel like a lot of games require an hour or two of dedicated play to accomplish much of anything and I hate feeling like I'm letting my group down when I have to leave early for RL reasons.

I'm not necessarily looking for a true MMO anymore, though I have tried almost all the major ones (paid and F2P).

I find myself leaning more towards games like League of Legends and World of Tanks these days, mostly because of the quick matches. I don't particularly care for the PVP aspect or the limited feeling of immersion that accompanies such a lobby-based game, but I don't think I have much choice.

Are there any PVE games that would fit this? Again, it doesn't necessarily HAVE to be an MMO (and I'm not counting things like heroics/scenarios/etc that are only part of a bigger game), but it definitely should include grouping and a decent "match-making" system or similar.

Thanks.