I think what matters more is which shop you go to. The neighbourhood shops around my area that I've tried gave me lackluster results. After I switched to a shop @ city hall area suddenly my pictures rock =)
Plus some shops can give you a white border around your picture. I like this.
EDIT: This is for colour negative film. When developing B&W I go to yet another shop. And for slides, I develop at my neighbourhood shop. Can't tell the diff between the "pro" shop, and my local shop is much cheaper somehow.
HTHs!
Alvin