Lol I was about to link Doubleagent as well.
Otherwise, this guy:
http://eu.battle.net/wow/en/character/perenolde/Fartzwrgoben/statistic#128:136
I guess he must bot a lot. Either that, or he is truly insane. 1.8 million honorable kills--the highest in record as far as I know--on just one character. Here I am feeling good about having 200k across
all my characters.
I remember when he was still sub 1 million. It seems he doesn't stop. Some people did the average calculations, and it turns out he has to play for a ridiculous amount of time each day to have gotten that many kills. Considering he also does PvE and junk, I have no clue how he does it. Actually, maybe there is one way:
In Wrath, there was a character on Destromath, Axt (no longer on that server), who had 100-0 in 2v2 (or it might've been a team, I don't remember if he played in it or not). Either way, it is pretty insane to have that consistency. I have a screenshot, but it is somewhere on a different computer. Bear in mind, ele shammies were ridiculously strong at this time, but their ISP's should get medals for not dc'ing.
Then again, it could've been a win-trade (I'm guessing it was, but no one would make it that obvious).
Also, there was that one asian or russian player who "completed the game" by getting all achievements. There was one he couldn't get because of a bug, but he abused a different bug to compensate for it. It is pretty rare to see someone who was completed a majority of both PvP and PvE achievements. Usually when I look at people's armories, they are either full in most categories except PvP, or they are full in PvP and low in all other categories (like mine xD).