Best:
New NWA - stylish and modern
Aeroflot - much better then the old one, great use of the Russian flag colors
Good
Norwegian - nice use of tail space
KLM - clean and very blue (I like blue)
New United - stylish, although the old one was pretty good as well
Ugly
US Airways - so, so boring
Southwest - too much Orange
Air India - At least judging by the few Air India planes that I saw, they haven't updated the livery for a long, long time