When he was three will still lived in DC and went to a very "ecumenical/diverse/culturally sensitive" church (it was a weird but great mix). So we sent out party invitations that read "Three at last! Three at last!"
One of my favorites though was the "Under the Sea" party. If I can ever figure out how to post, I'll scan and post in the picture of this incredible cake my wife made. We did snacks with goldfish and gummy worms and more...
This year he turned 13...sigh. He had four friends over and we fed them subs, then took them "Cosmic Bowling" at midnight and after that did a scavenger hunt at Wal-Mart. This guy in his 20s at the bowling alley told us we were really cool and he wished his parents had been like us...