A few that spring to mind are.............
Mary Dekker - US 1500 metre runner 1984 LA olympics after the Zola Budd incident - Her pathetic performance of crying for about 6 months after the race was one of the worst i've seen.
Mike Tyson - Ear eating incident - say no more
Greg/Trevor Chappell - and their attempt to play lawn bowls on a cricket field
Richard Loe - NZ rugby player and his horrible eye-gauge of Greg Cooper in the early 90s
Johan le Roux - South african who bit Sean Fitzpatricks ear