I use my local pro shop
McGreevy Pro Lab which is a great lab, they do mail order, but aren't really cheap. That said, ANYTHING you need done from film or digital they can do. While they are too expensive for me to use on a regular basis I am lucky to have a lab this good so close.
The lab I typically use, and have had no problems with as well as being relatively inexpensive is Carl's Darkroom in Colorado. He even has very very very fair pricing on push and pull processing assuming you send in a few rolls. Many places charge a few dollars to 2X the cost per roll to push process but Carl's does it by the rack. So 3 rolls of 645 for $3.50 or 5 rolls of 35mm for $3.50 is really a very fair price.
Beyond that turnaround time is great. Just about a week going priority mail both ways.
A place that I've heard decent things about but not used myself is NCPS they have pretty decent prices and offer a bit more services than Carl's does.
Honestly, while a full service photo finisher is great, all I really need is quality E6 processing. I do the basic scans myself, and occassionally have a wet mount or drum scan done at a lab. Beyond that simply upload your final images to MPIX.com and wait for FedEx to arrive! Never had a problem with my calibrated images from MPIX.