Just spent a good deal of time writing this answer to another post...thought I'd put it here too.
I'm a photographer but to make ends meet, I operate an estate managment company and with this come a good number of clients that have found old film in a persons belongings after a death. I've become a bit of an expert I think. This is my experience.......
Rocky Mountain is very slow (6 months to a year and a half), expensive and do little beyond processing your film in a developer that would have been appropriate for the time period but does little to compensate for the age of the film. Prints are then made on a mini-lab onto conventional color RA4 paper. You pay full price regardless of the results. They do seem to have the experience but it seems like they really don't give a damn. Though the most popular and the most recommended of all the places doing this work they are best avoided.
Process C-22 is run by an individual who is competent and truely seems to enjoy his work and have concern over what type of product he puts out. The turn-around time is not fast but hey....do you really need a fast turn-around on film that is 40 years old. Most film is developed in a developer that renders a B&W negative regardless if it is a color film or not. This is an appropriate approach with undeveloped vintage film as the silver content that is normally bleached from a color film is far more resilient over time then the color dye image. All work is scanned from the negative and digitally enhanced before it is printed. Your will pay for development regardless of results though you will not be charged the scanning and printing fee. Seems fair enough to me. Beyond the fact he's overseas he's an excellent option.
Rapid Photo. They're name is correct. Of all the places offering this service they are the fastest though by experience not as fast as they claim. The folks here seem competent enough and the phone service is good. If they are unable to salvage anything from your film you will be charged the developing price only. What I do like about thier service is that you pay only for the prints that they do. What I don't like is that if you pay by check the full price, assuming all of the pictures worked out getting a refund for the difference is unwieldy. They do include a cd along with prints but this cd is scanned from the print and not from the film. Much improvement can be made in the digital realm to these distressed images so this is an unfortunate approach. If you need your film back quickly this is the place to go to. I would recommend process only and then plan to take the time to do your own scanning (contrary to their claim that scanners will not scan negatives of this density...most can) so you can do some very necessary corrections before you output to paper.
Film Rescue is the most expensive of all of the above but in this case you do pay for what you get. They are moderately slow (6 to 9 weeks) but do tend to deliver about on time. As mentioned, you will pay more here then anywhere else but you will pay nothing if they are unable to salvage recognizable pictures from your film. Sounds like good motivation to do it right. I also like that if your film is bordline to the point the images may not be recognizable they do call to consult if you want to proceed with the digital work. If you say no then....no charge. Your recieve back prints, negatives and digital files on CD-r. The price includes age appropriate development, scanning from the negative, digital corrections and return postage though with the price that they charge I don't think including the postage is that big of deal. If you want Cadilac service and the film is important to you then this is the way to go....that does come with a price though.