Fans of the Warhammer franchise of games (myself included in that group) can be darn annoying at times. TT Warhammer players have a certain rep of course, but I seldom see the same being said for folk who like games such as those in the DoW franchise. Can't really speculate on Warhammer RPG players (Fantasy Roleplay, Dark Heresy, Rogue Trader, Deathwatch, etc.) as the forum/Net presence of such folks is usually fairly moderated on the sites I pay attention to.
Warhammer Lore nuts are certain to make themselves annoying when things diverge from canon. There was also all the hoopla about WAR a while back... something even I still complain about from time to time.