Here are a few nice things we've heard:
"You are the only contractor that has respected my home...and me."
"It's so nice to hear a smile at the other end of the phone line."
"Thank you for working with me and my disorganized finances."
"I don't know what I'd do without you to help me."
"Very impressive and knowledgeable."
"Thank you for everything!"
"He showed up on New Year's Day to fix my problem!"