Probably my most memorable vote kick was with a guilded group of 2, who were getting their jollies by doing everything they could to wipe the group. They kept harassing the 5th member of the group, a mage, about his dps and whatnot and repeatedly tried to kick him. The vote wouldn't pass because my friend and I kept hitting "no" but they insisted on trying to kick him. Solved the problem by telling my friend to hit "yes" on the next vote, started my own vote kick on one of the guildies, and for the reason typed in "crappy mage." A few seconds later, sell wow accounts to the vote passed and one of them was gone. After a few minutes of the other guy raging and crying he left the group too but I couldn't stop laughing.
First time I was ever vote-kicked was actually last week, I think, for a legitimate reason in a sort of unusual situation. I was hanging out at my parents' house, running ToT as a healer, and in the middle of a boss fight, my dad comes running in from outside saying that one of their dogs had been bit in the face by a rattlesnake. So I quickly told the group that I needed to go and why and logged out. I assume/hope they understood, but I didn't think to drop group in my rush to help my dad take care of the dog so I imagine they probably eventually had to buying wow gold to kick me for being disconnected, which is obviously understandable.
The dog is fine by the way. It was touch and go for a bit and she was at animal emergency for several days, but thankfully they took excellent care of her and she's home recovering now.
In Cataclysm I queued for a random with a fellow caster - we were thrilled to get the heroic which dropped a trinket we wanted for raiding (back then queue times were typically 45 minutes for dps; this was before buy world of warcraft accounts satchels, instance nerfs, or limits on guild groups kicking people). The other three members of the group were, of course, from the same guild - paladin tank, a melee (class I forget), and a priest healer. They stood around for a while and then made some snide comments in an attempt to get us to leave, when we wouldn't they said one of us had to go (if the trinket dropped it was for the priest) so they could get someone else to kick the one that stayed. I was eventually kicked and my friend dropped group in disgust - we levelled our tank and healer quickly afterwards.