My little brother was my best man. He was bricking it before the speech and had a 'few' drinks to calm him down. By the time he got up he'd drunk about 4 pints, half a bottle of sherry and several whiskeys.
The speech was brilliant. He swapped between whispering and shouting, fluffed all his lines, dropped his cue cards, used my ex-gf's name for my wife, forgot my name, then gave up towards the end and started crying. I don't think i've ever laughed so much in my life.
And just so you don't think i'm a totally heartless b'stard, I rescued him when the tears started to flow, finished the toasts. got him some grub and set him up with one of the bridesmaids.