1st post so don't flame!
GSP has more dynamic stand up
GSP has probably better wrestling, however, it's quite close
GSP is very effective on top pounding
Sanchez is probably the more effective submission grappler, although close
Sanchez is very tenacious, always coming forward, not seen many pushing the pace on St Pierre
Sanchez has improved stand up, I think he could definately survive, but his best chance of winning would be scoring the take down
Both are very difficult to take down, although I think Sanchez is weaker in this area
This fight would probably be won on who can get the take down and implement their top game, however, I would say GSP has the best chance of scoring a KO/TKO.
Think this is one of the best fights the UFC has at the moment!! I would pick GSP, but a very close fight........