I've only ever used one:

Mike Caro's Substudio smile

He's a fantastic musician on a variety of instruments, he can do many different genres, he listens to you and captures the sound YOU are looking for, and his prices are very reasonable. Oh yeah, he gets stuff back to you quickly too.

Working with Mike has been nothing but a great experience!

You can also see that he has a lot of class, in that he responded to your query by giving advice without advertising his own services. That same attitude applies when you work with him as well - he will be upfront and tell you when something isn't ready to demo.

You won't go wrong with Mike!

Scott