Dragon Age is a must have if you've never played it.. Seriously, you won't be disappointed.
If you liked Oblivion you might wanna check out Fallout 3 or Fallout: New Vegas, not both, because they're nearly mirror images of each other I played the hell out of 3 and have a problem getting into NV because it feels like it's the same game that I've already put in hundreds of hours into. If I had to say which one was better, I'd have to say NV, because there are more weapons and more content to play around with than 3.