I finished up my first playthrough of Dragon Age: Origins on Sunday morning. Aside from a few bugs and a slightly unpredictable difficulty curve, it was a very enjoyable experience. I was expecting something in the style of Mass Effect, but it turned out to be more like Knights of the Old Republic or Neverwinter Nights 2; Unexpected, but not unwelcome.
Assassins Creed II is up next. I'm a couple of hours into it already. They've definitely made some improvements over the original. Combat seems better. The additions of more sandbox-style gameplay is nice, with actual missions instead of the formulaic structure it had before. Ultimately it feels less linear and more varied.