I've now seen 2 A5 Audis on the road, and they are really, really striking! They look good from every angle! Also, owning an A6, Audi interiors and their quality is probably the best of any car made!
The 335i coupe is also beautiful, and looks good from every angle as well. In typical BMW fashion, the interior is well made, but a little cold and slightly boring (as are most new BMWs...my new X5 is drop dead gorgeous, but the interior is cold & flat).
The new C-Class is in my opinion, the best looking new model Mercedes on the road. It has major road presence, and the build quality is A+. The only problem is that it comes standard with MB-Tex interior. Most people will think it's leather, and the stuff lasts with NO maintenace for like 30+ years, but if you are used to buttery soft leather, you will feel ripped off. I think leather is an extra $1000.00, and 99% of all C and E Class models sold in the US, come standard with MB-Tex..and Germans are really cheap, so I'm sure all models in D-Land have the fake leather. It's a quality, durable product, but I think leather should come standard with a Mercedes-Benz. Also as of late, Mercedes quality & reliability has been excellent, and I think will suprass BMW.
After all that....I would go with a Montego Blue 335i coupe!