I have dual Crucial M4s (One for OS X and the other for Win7) - Both work brilliantly!
Initially, I had one drive for both Win7 and OS X, but this really did not work well at all! Therefore I echo Coupz in saying go for dual drives, double the cost, but will be much more robust and you wont regret it.
Cannot fault these drives one bit...I do a lot of photo and video editing in both OS X and Win 7 and I have never had any problems with them (touch wood).
I believe SanDisk 120Gb is pretty good also, but don't have any experience with them - maybe others could comment on this.
Hope this helps.
J