My LBS, Cronometro, has stopped using Pro Link and now uses Rock-n-Roll Extreme. I hold their advice in high regard - as they are the Bikesport of Madison, WI.
We do tend to use a lot of T-9 Boesheild. It seems as good as anything. I agree with madisongrrl on the Pro-Link thing. It can get pretty darn dirty pretty darn fast.
Hey, madisongrrl, are you like, Madison Bell from "Swim Fan"?
Yep, Prolink makes for a silent drive train. Oh Joy. Just remember to wipe down your chain after application and before/after every ride. It's a small price to pay for smooth and silky silence.