If you aren't playing Borderlands 2, well, I guess that's ok, but I feel like you're missing out.
I'm solo-ing it, mostly. Gunzerker.
I find it to be a perfectly enjoyable way to play, despite the advertising. The Pandora of Borderlands 2 is a bigger one than the last, its locales many and varied. I feel like I could spend quite a bit of time there, covering everything in corrosive goo and flippin' the dualies.
I'm also playing it on the PC and, if you are too, if you can, if you have a card that supports the advanced Phsyx stuff , TURN THAT SHIT UP. Well, on. Turn it on. In a game that tasks you with causing mayhem on a regular basis, why not have that mayhem be as chaotic as possible?