hahahaha, i agree with your list even though sometimes i do stuff on it :P 

btw i quoted you on purpose

Hahahhaha now everyones quoting the OP

naa dude gaming fanboys in general are all A-holes. and by gaming fanboys i mean anybody who really likes video games and talks about them much. these people are just annoying as fuck...

Pretentious assholes who think they're interesting and/or funny when they're not annoy me the most.

Would also be on my list. Thankfully they seem to be leaving, sticking to certain forums or getting banned more often. Yey mods!

Unless I missed it, nobody has mentioned the classic "I don't care about sales" type.

Here on this site that's all about sales.

Some good points in the OP, and I'd personally add:

1. People pretending to be interested in or even be fans of something just to get a chance to hate. on it or it's fans. C'mon, it's not like you're fooling anyone...

2. Victims. Some people act like the whole world is out to get them. They are always being treated unfair and there are conspiracies against them everywhere.

3. People with a love for generalisation. One fan saying something = a whole fanbase saying something, and for some reason they always look for the worst ones to be the representatives. According to these people a fanbase is ruled by some kind of overmind, making them all share the same evil thoughts.

4. There are people who just hate whenever a certain game/console/company gets a lot of love. It's like they have some kind of disease giving them extreme internal bleedings whenever something positive is said about said game/console/company.

Nice list! I don't agree totally, but I hate the quote trees the most: unless they're totally needed to understand the discussion (for example if the last quoted post is some pages back and not easily findable) they are annoying. The necessity to follow the thread or subthread can be satisfied with one long quote every one or two pages, but the successive comments can have the tree trimmed to the last few posts. Also, most times, just a part of the previous posts needs to be quoted.
BTW I'm sometimes guilty too of not trimming those trees enough, sorry.

Number 2 definitely. I mean the first coupe of times was ok, but I was here in the olden days, and really I don't see it. Worst thing is that they complain about EVERY TINY change like the points and badges systems, I mean come on!

TEH C3LL is controlling people :O