I just watched the top 10 dunks and top 10 blocks of 2008/2009 on nba.com. The top block was by the birdman on a Rudy layup attempt (you all remember the disgusting hair-preening celebration afterwards), and a few of the top dunks were on Przybilla, Oden and Aldridge.

top 10 blocks: http://www.nba.com/video/channels/nba_tv/2009/07/31/nba_20090708_top_ten_blocks.nba/

top 10 dunks: http://www.nba.com/video/channels/nba_tv/2009/07/30/nba_20090630_top10_dunks.nba/

At least Roy has the #1 dunk!