The Randy Johnson/bird confrontation would probably be high on my list.
Along similar lines, wasn't there an incident years ago where Dave Winfield (then of the Blue Jays, I believe) was charged with cruelty to animals when a fly ball that he hit into the outfield struck and killed a bird in flight?
Of course, high up on the most bizarre list must be the Cal/Stanford game back in the early 80's when the Stanford band rushed the field during the last play of the game, and the Cal guy ran it all the way back, dodging and weaving his way through the mass of humanity that littered the field. I don't think yet that Stanford's lived that one down yet.
Tom at MSY
"The criminal ineptitude makes you furious"-Bruce Springsteen, after seeing firsthand the damage from Hurricane Katrina