The S65 absolutely stole the show for me. Beautiful ground kit, fat AMG 20s, and 600 odd HP and over 700lbs. of torque was enough to make me drool. The car has an unbelievable presence, and I can honestly say that it is my dream four-door.
Unfortunately, I wasn't as impressed with the M5 as I thought I was going to be. The color they had at the show was a horrible crap brown (called Sepang Bronze Metallic). The interior looked nice, but was disappointed that BMW didn't give it the full-leather treatment (dash) like the previous generation. It still felt a little plasticky. But I think overall the M5s look great on the road or when they're parked. But I think the S65 stole a little bit of its thunder for me....same goes for the CLS55, which looks very impressive and comes with a full-leather interior, and as we all know, it no performance slouch either.
Audi's S8 was at the show, too. Another very beautiful and impressive full-sizer.