I thought Chris Bosh did a good job defending Dwight Howard in the post in the playoffs last season (07-08). Perk did a much better job, obviously, but Bosh did better than most opposing centers do.
Most of Howard's points in that series came off dribble penetration. A lot of drive and dumps, alley oops, and a large number of offensive rebounds.
Bosh was fine when he was allowed to defend Howard one-on-one, and got torn apart when he had to try and help his teammates who were being cut apart on dribble penetration.