This Sat I have #5 in a 10 team PPR. Assuming LT, SJ, LJ & FG go 1-4, I am leaning towards Westbrook, but his weekly status has caused me ulcers in the past - I just like the guy. Willy is getting more and more love so he's crept onto my radar. Bush isn't a bad option here either although I don't see myself going that direction. Addai doesn't do much for me, but there's an arguement for him at 5, too. I think any of those could be easily defended.
Personally, I think Westbrook has the most upside of this group, and probably the biggst (injury) risk to go with it.
FWIW, I currently plan to go RB, RB, WR, WR, RB, WR (we start 2 RB, 2 WR, and 2 flex). If Gates is there in 3 I may grab him, but otherwise I'll hold off and take the best available in the middle rounds.