I only have experience with Hinkle printing in Corbin, KY, which is a bit of a drive from Lexington. They were incredibly helpful and prompt in responding to emails.
I can't vouch for their quality, as I designed and printed my invites at home. These are just the two that popped up on google that I recognized their name.
Thoroughbred is great, Mike Abbott is extremely nice and easy to work with.
But personally, I'm getting mine printed at Post Printing. I use them for my graphic design job and they have never failed to give me excellent quality and color on every job I've ever had done by them.
Re: Printer in Lexington Area
Here are a couple actually in Lexington:
http://www.minutemanlex.com/servicecenter/products_services.html/title/invitations
http://www.thoroughbredprinting.com/
I can't vouch for their quality, as I designed and printed my invites at home. These are just the two that popped up on google that I recognized their name.