Lords of Karma

While I thoroughly enjoy Wilfred Fizzlebang in the Lord Jaraxxus fight in ToC... my favorite NPC in all of WoW is, without doubt, Millhouse Manastorm.

http://www.wowwiki.com/Millhouse_Manastorm

Why you ask? Simple.... "I'm gonna light you up Sweetcheeks!" (see above link for all the Millhouse quotes.. they are awesome!)

GO GO GNOMES!

Millhouse is way up there.

I also liked the rogue academy person in Shattrath, talking about how mace rogues weren't welcome at her school because how could you be sneaky smashing brains out onto the floor.

As someone who has done alot of Horde playing as well, Mankrik's wife is also highly rated due to the massive outrages caused by noobs asking where she is in Barrens chat.