I have always been thanked by the folks I return stuff to. An older couple I returned a wallet to took all the money out and gave it to me. At first I refused it saying I was simply doing what was right, but the old lady looked at me as if she were about to cry, so I gave in and accepted it. It was only 25 bucks, but must have been a lot to them I'm sure. I gave it to my favorite charity.
Picked up a phone in the middle of the road, then a wallet a few feet further down the road and then a few business cards. The owners house was just a couple hundred feet down the road according to the drivers license. I put it on the step by the door and just as I was leaving the owner pulled in his driveway. He was a parole officer and had left the phone and wallet on the top of his car. Very appreciative he was that I rescued his phone from potential disaster. Offered me twenty bucks, I declined. Then it was a case of beer, declined that, too. I am sure he had a good day going forward.