I have the original PS2, XBOX release, and PS2 Greatest Hits version.
The Greatest Hits version is the best. Why?
It has everything the Xbox version has, sans the per-pixel flashlight, which doesn't matter.
It retains the FMV cutscenes from the original PS2 version.
What's wrong with the Xbox FMV?
They are shitty WMV encoded, so they are noticably grainy.
They run at 30fps. Maybe you think that doesn't matter, but check out the 60 fps PS2 FMVs and then come back to me. (this is FMV framerate, NOT in-game framerate)
The sound gets out of synch. In fact, the rolling spoiler movie is so long that they removed the voiceover all together in the Xbox version, since the voice was never going to synch with the lips anyway.
Get the PS2 Greatest Hits version, the clear winner, unless vertex lighting explodes your head, or something.