His 1st favorite moment was when he got married to Caitlin. Bones 2nd favorite moment was getting the honorary doctorate and the moment he was current living in. Then his 3rd favorite moment happened in the same building as the graduation ceremony. It was when he ran into Coach Pittman at the urinal and Bones really wanted to talk to him, but since it was at the urinal there were rules. So he waited, and then when they both washed their hands, Bones said "Woo pig!"
Listeners can watch Bones detail these moments during his speech at the clip above!