For me, Michael Stipe in R.E.M.'s "The Sidewinder Sleeps Tonite"
His giggle is at the 2:30 through 2:34 mark in the video, right after he sings "or a reading from Dr. Seuss."
I love the song, cool video and Michael looks hot as always.
I love it when questions get revived on here! I wish it happened all the time.