When I first thought about this question, I was very interested in who it was. So here are the results.
Points: 1. Kevin Durant 29.6 PPG
2. Carmelo Anthony 29.4 PPG
3. Kobe Bryant 28.4 PPG
4. Lebron James 26.6 PPG
PPG = Points per game
Rebounds: 1. Dwight Howard 11.8 RPG
2. Zach Randolph 11.6 RPG
3. Joakim Noah 11.3 RPG
4. Nikola Vucevic 11.2 RPG
RPG = Rebounds per game
Assists: 1. Rajon Rondo 11.1 APG
2. Chris Paul 9.7 APG
3. Greivis Vasquez 9.3 APG
4. Jrue Holiday 9.0 APG
APG = Assists per game
Blocks: 1. Larry Sanders 3.07 BLKPG
2. Serge Ibaka 2.79 BLKPG
3. Tim Duncan 2.74 BLKPG
4. Roy Hibbert 2.64 BLKPG
BLKPG = Block per game
Steals: 1. Chris Paul 2.56 STPG
2. Mike Conley 2.29 STPG
3. Jeremy Lin 2.04 STPG
4. Monta Ellis 1.91 STPG
STPG = Steals per game
Here is the site I got the information from:
http://espn.go.com/nba/statistics