Ben Wallace.
Anyone who can grab 4+ offensive boards/game over a 4 year span gets more to me than a great defensive rebounder.
BasketballReference.com has a stat called Rebound Rate.
"Rebound Rate is an excellent stat for measuring the rebounding ability of a player. It simply measures the percentage of missed shots a player rebounded while he was on the floor. Rebounds allowed by opponents was not kept as an NBA stat prior to the 1970-71 season so rebound rate is only available after that year. It was used by John Hollinger in his book Pro Basketball Prospectus and I encourage anyone interested in this statistic to check out his book."
The top 10 the last 4 years have been
2003-04
Player Team REBRATE Year
1 Danny Fortson DAL 21.8 2003-04
2 Erick Dampier GSW 20.8 2003-04
3 Kevin Garnett MIN 20.2 2003-04
4 Ben Wallace DET 19.1 2003-04
5 Tim Duncan SAS 19.1 2003-04
6 Marcus Camby DEN 19.1 2003-04
7 Tyson Chandler CHI 18.9 2003-04
8 Reggie Evans SEA 18.8 2003-04
9 Jeff Foster IND 18.4 2003-04
10 Carlos Boozer CLE 18.3 2003-04
2002-03
Player Team REBRATE Year
1 Ben Wallace DET 23.2 2002-03
2 Vladimir Stepania MIA 20.1 2002-03
3 Marcus Camby DEN 19.8 2002-03
4 Kelvin Cato HOU 19.7 2002-03
5 Jeff Foster IND 19.5 2002-03
6 Reggie Evans SEA 19.2 2002-03
7 Etan Thomas WAS 19 2002-03
8 Tim Duncan SAS 19 2002-03
9 Kevin Garnett MIN 18.8 2002-03
10 Brian Grant MIA 18.3 2002-03
2001-02
Player Team REBRATE Year
1 Danny Fortson GSW 21.8 2001-02
2 Ben Wallace DET 21.1 2001-02
3 Tyrone Hill CLE 19.8 2001-02
4 Kevin Willis HOU 19.7 2001-02
5 Jahidi White WAS 19.3 2001-02
6 Marcus Camby NYK 18.6 2001-02
7 Lorenzen Wright MEM 18.1 2001-02
8 Tim Duncan SAS 18 2001-02
9 Kevin Garnett MIN 17.9 2001-02
10 Vladimir Stepania MIA 17.8 2001-02
2000-01
Player Team REBRATE Year
1 Dikembe Mutombo ATL 22.6 2000-01
1 Dikembe Mutombo PHI 20.8 2000-01
2 Michael Smith WAS 20.6 2000-01
3 Marcus Camby NYK 20.5 2000-01
4 Ben Wallace DET 20.4 2000-01
5 Popeye Jones WAS 20.3 2000-01
6 Nazr Mohammed ATL 19.7 2000-01
7 Jahidi White WAS 19.1 2000-01
8 Jeff Foster IND 19 2000-01
9 Jerome Williams DET 18.5 2000-01
10 Corie Blount GSW 18.3 2000-01
While Danny Fortson has been the best rebounder twice in the last 4 years, only one player has been top 4 four years in a row. BEN WALLACE.
He did that while leading the league in total blocks in 03-04, 3rd in 02-03, first in 01-02, and 8th in 00-01.