I have fed Pro Plan for many years and with good success. Note, there are a number of varieties of pro plan out there, and I have only fed Performance (Chicken/corn and the fish/rice formula). It is a good food, and can be found almost anywhere. Additionally, Purina and their Pro Plan brand is also a very large sponsor of dog performance events, which is a good thing. Personally, I feed Orijen. It is very spendy, super high quality, but most importantly, it makes my dog run at her best.
Asking about dog food is like asking what is the best shotgun to buy. You will get lots of suggestions.
I suggest you do your research and then go with what works for your dog, budget and philosophy (natural, mostly meat, brand recognition, organic, etc..).