Although there is a native build of PCSX2 for Mac OS X it is dated. So I built an app bundle via wineskin using the latest *stable* Windows binary of PCSX2 (0.9.8-r4600). The results were to my liking, therefore I made this incredibly BORING video of the emulator running the intro to Final Fantasy X. The game is rendered to the screen in a resolution of 720p and looks very nice. Especially compared to the original on a legit PS2. I used the ZeroGS and ZeroSPU2 plugins for video and sound.
I played the game itself for about 30 mins and only noticed very small graphical anomalies.
Dolphin Emulator - http://www.dolphin-emulator.com/
PCSX2 PS2 Emulator - http://pcsx2.net/
Mac PCSX2 Native App - http://pcsx2mac.net/