I'm gonna have to say the Audi. If they had slimmed down the CTS-v Coupe like the XLR-v, it would be a different story.
It's too frumpy, and though it's powerful and "elegant", it looks nothing like a supercar. I don't want woodgrain on the dash of my Nurburgring-destroying auto, nor do I want three feet of door panel from bottom to top.
I think Cadillac's styling is a little long in the tooth, anyway, so I'm sure that's got a lot to do with my opinion.