I don't totally get the hate for Ray Allen. It bugs me a bit that he went to the Heat, but let's not forget that Danny Ainge spent like 2 years trying to trade him before he got fed up and left.
Don't get the Buckner hate either. Maybe I was just too young, but Buckner tried his best in a bad situation and screwed up. Shouldn't have even been on the field in the first place. Seems petty and lame to vilify someone for trying his best and failing.
If we're talking justifiable hatred, let's start with Roger Clemens. **** that guy.