I buy into the protein for recovery philosophy. I used to lift some weights in my youth and started on GNC post-workout protein drinks then. To this day, I'm still whittling away at the upper body mass built back in 1993. I learned that if your workouts consist of repeat until failure, and then you consume copious amounts of protein immediately afterward, you build muscle.
I've tried a bunch of different proteins but keep coming back to GNC's house brand. Currently I use GNC Pro Performance Whey Protein, in chocolate. You're supposed to add it to water but I shake it into skim milk instead. It's creamier and tastes like a milkshake.
It's best after extended or exceptionally difficult workouts. Most of my current early AM 1-hour rides don't warrant 75g of protein within 3 minutes of getting off the bike. But it's always with me on game day - I fill a Nalgene bottle and keep it in an insulated bag, packed with ice, inside a cooler also packed with ice. Cold, refreshing and satisfying after a hard race, and I'm completely refueled before most guys even have their helmets off. Plus, it keeps me from filling up on junk from the nearest conveninent or fast food store, which is the inevitable alternative to leaving a race hungry.