Jason Kidd. Not just because I am a Maverick fan, but because Kidd has set NBA triple-double records this decade, surpassed Magic Johnson on the All-time assist list, and has been consistantly an All-Star caliber player up until these two recent years, where he still hasn't been bad.
Chauncey Billups has won an NBA title plus Finals MVP awards, been a consistent All-Star, and revamped the Denver Nuggets, but in this decade, Jason Kidd has cemented his future position as a Hall-of Famer. His name is literally among greats.
It's Jason Kidd, and not by a hair.