Yep, I'm the same way. I know what I like, and I've never been good at branching out. And then a solid sprinkling of 'I've started a game, now ooh bright shiny new game, wait, what was I doing in the old one oh crap I don't remember time to restart'.
I'm really enjoying TW3 though! My Era Secret Santa got it for me, and I'm doing Family Matters quest atm, which I've heard fantastic things about! ...But I mostly just keep getting distracted and running off into the wilderness to discover what is at each ? point...