One of the things that make my blood boil are people who let everyone in the game let everyone know absolutely everything about their life. Along the lines of 'I did this, with that person last night' and go into detail about it. Yes its lovely that you did something, no Im not envious and Ive literally gone 'Im sorry..Im all out of f's to give but you can ask another, to see if they have any spare for you.' I understand there is of course a social aspect in guilds, knowing eachother better and the other various things but still...I dont want to hear -in detail- about what you do and how you do it.
I guess another thing that irks me would be people that gloat with their experience in any online game, be it an RPG, FPS, RTS..any other type. Yes Im happy for you, yes I do believe your a good player, just please stop telling me round the clock every single time you get on how far you got in this area, what you did 5 years ago, why your tactics in that were so far superior to everyone elses. These are usually also the type of people, who for the life of themselves cannot adapt to new tactics or ways whatsoever.
'Well in my old guild, we did it this way.'
"kk, but we are not in your old guild..and here..we do it this way"
'Well, the way we did it when (goes into long drawn story about how it took so and so long for everyone to understand it and they finally made it and oh btw, they were the first on the server, and the best..and the fastest...'
"Ok, thats lovely, but by now we've all done this like 10 times or so, and everyone found this to be the most simple way."
'yeah but, (goes into another story)
^-----it makes my blood boil