I have used Colourworks for 70mm C-41 developing, and they were excellent. I have had E-6 done at Philadelphia Photographics, and they have top-quality processing as well. $7.00 a roll is not bad either.
Philadelphia Photographics used to be fantastic for 120. Around mid-2010, their handling of the film became somewhat haphazard; I lost a couple half-frames at the front of rolls (obviously exposed to light during their development process). I stopped using and recommending them.
Hopefully that was a temporary problem and it's been fixed; I'm just about to give them another try. They're damned conveniently located for me.