Hard to say who is the best, Price is certainly up there with two or three others. For those who like stats, here is an interesting snapshot. Metres per game and tackles per game - two key prop duties - from the 2007 NRL Season Guide. 10 props chosen.
Metres per game
Price 155
Civoniceva 140.5
Kite 128.5
Ryles 128.4
Bailey 127.8
OMeley 124.8
Clinton 123
Asotasi 116
Wiki 101.7
Kaufusi 76
Tackles per game
Bailey 29.3
Ryles 25.4
Civoniceva 25.2
Clinton 24.3
OMeley 22.8
Kite 22
Wiki 21.1
Asotasi 20.9
Kaufusi 20.6
Price 17.2
Metres per game
Price 155
Civoniceva 140.5
Kite 128.5
Ryles 128.4
Bailey 127.8
OMeley 124.8
Clinton 123
Asotasi 116
Wiki 101.7
Kaufusi 76
Tackles per game
Bailey 29.3
Ryles 25.4
Civoniceva 25.2
Clinton 24.3
OMeley 22.8
Kite 22
Wiki 21.1
Asotasi 20.9
Kaufusi 20.6
Price 17.2