The all around best Power Forward in the Game right now is Keving Garnett. He does more (solely) for his team and single handedly leads them to victories and the postseason a couple times. He has never had any talent around him at all and has to carry his team more than the rest. He is a better rebounder than all of those guys, a better scorer than all of them (except dirk, and maybe amare).
I think that Amare and Dwight Howard have the potential to be better with time. I think Tim Duncan is the most fundamentally sound PF in the game (but he plays as a center more of the time) Bosh, Boozer, Pau, Wallace, Randolph are all great but not super to the level of the rest. (Odom is a SF). Although Boozer is having a breakout year, he's not well-established enough in the league. This year, the answer could very well be Dirk but he has a lot more talent aroung him then the rest of the guys (except Amare maybe) which makes it easier for him to shine, although he still doesnt rebound, block, assist or shoot at higher percentages than KG (all the things you NEED your pf to do). He's like a 7 ft. shooting guard.
Brand would be a close second to me but all around, i still would take KG any day over the rest if i was building me team!