The Cadillac CTS was built on the new sigma platform (using Japaneese style manufacturering). It has aggressive styling and lots of power. Its handling is superb - it feels like is is on rails around corners.
Its seats and backseat leg room are great (better than in the BMW 3-Series, Mercedes C-Class and the Lexus IS250). Having driven all of those I have zero regrets about my purchase. My only negative is that the dash could have a little better design (especially if you have the base stereo and no navigation). Cadillac service is superb as well and they really take care of you.
XM radio, leather seats with power lumbar support, seat memory for passenger and driver, customized greeting display when you put in the key, the tiptronic manual shift works great and makes the automatic a fun "stick" to drive, the radio "wheel" for volume, and programmable buttons on steering wheel.
Redesign the console for those without the navigation system. The space is just filled with cheaper plastic (even though I have beautiful wood everywhere else).