Happiest - Mavericks 2011 NBA title win
Saddest - MJ retiring in '93 and '98
Angriest - Mavericks losing in first round to Golden State as #1 seed in 2007/Mavericks blowing the 2006 Finals

@ Paul Pierce + wheelchair. They were carrying him out like a beached whale as if he'd blown out his kneecap. Then he trotted back out like 2 mins later and nailed a few threes as if nothing wrong. If there was a "funniest" category in this thread, that might be my nomination.