I looked at 3 tires in the stock 205/50/16 size:
Bridgestone RE730
Dunlop SP Sport 9000
Toyo Proxes T1-S
Both
www.bimmer.org and
www.audiworld.com have message boards for tires. From what people say, the RE730's are pretty good but become noisy. The Dunlops are supposed to be more quiet, but they do cost a bit more. The few people who have the Toyo's have been happy with them.
I got the Dunlops because Tire Rack carries them. The compound is noticeably softer than the stock RE92's. I feel they are quieter and stickier, but I've put less than 500 miles on them so far.
Looks-wise, the Dunlops look not as wide because 205 is not that wide to begin with, and the Dunlop's has 2 circumferential channels which makes the tire look taller from the rear. The Toyo's would probably make your tires look wider (and better, IMO), because the sipes go all the way from the center to the edge.