Kudos: from the Greek κύδος kydos (literally "that which is heard of") means "fame" and "renown" resulting from an act or achievement.

Hi Archie,
First of all I'd like to thank you very, very much for all your help in getting my home rented in such an expedited time.  You don't know the stress that I had, but thanks to you I can now relax.  Home Realty has really provided me with such great customer service and I am very appreciative of that.  You guys have really earned my business and I would not hesitate to use Home Realty again.  Thank you. 

Archie,
I appreciate your hard work for myself and my wife.  Thanks for all your work.  You are great.