SGTOOLS fanboy, because it's obviously a spyware

None and all. A person can be obsessed over something and be a very nice person at the same time. Yes, I've known "fanboys" which were okay. You can't really blame a person for loving something very much. Live and let live.

For me its probably any fan of Undertale.

Bronies. When I try to search for something on internet, I always end up with ponies >.< Nothing wrong with themselves tho, I just hate that I can't evade their content.

Fanboys are fanboys, the subject matter is of no importance. They're all obnoxious and refuse to listen to reason, so everyone hates them. Only fanboys tolerate each other IF they're fans of the same thing.

blizzard
LoL
Sony and Microsoft
Nintendo a little

All people who won't listen to facts and who polarize discussions. That includes politicians, religious leaders and fanboys.

Political fanboys I suppose would be my guess

Not necessarily because they're particularly worse to try to talk to, but more so because what they're fanboying about is actually something of some import. So to completely close yourself off to reasonable discussion and be completely unwilling to honestly examine your position on something that actually matters, you're doing yourself a pretty serious disservice as much as you are to anyone else around you or society at large.

Any fanboys which never listen to arguments, and even worse, try to convince you repietedly...

Any fanboys are bad, but Sony and PC master race bullshit warriors are the worst

The dank memelords are the worst, it's just too much these days! >:(

Undertale was obnoxious too around its release.

no pole?psshhtt. . .

...furries.... I don't hate all... but enough of them are just too cringeworthy...

Which fanboys are the worst?

I didn't know there were good fanboys...
Fanboys = bad, Fans = good, with no choice inbetween.

Blizzard fanboys are very annoying but there is NOTHING like an apple fanboy, specially the jobs ones

I don't think the majority of fans for any game (at least any that I'm familiar with) are particularly terrible; it's just that the obnoxious idiots in the minority are much louder and give the entire fanbase a bad name. Look at Dark Souls. Most players are very nice and reasonable, but there's the obnoxious fanboys who can't comprehend that someone may dislike parts of these games for anything besides the difficulty. It's really the same with any community with hardcore fanboys.

The ones I don't agree with at the moment.

League of Legends.

'nuff said

All the rabid fans who can't deal with the fact that someone might have a different opinion or taste, and keep bashing their opposing side. They all need to chill.

Apple.. dammned hipsters...
seriously though: Doesn't matter what they're fanboys of, the worst are the ignorant ones who don't care about reason

Poniz

Fanboism is bad, mkay. Can't tell whom I hate the most, but I can tell, which ones I like ^_^ - 21 pilots' ones.

As people said, most fanboys are annoying.

The ones that are most annoying to me though, are the Bethesda fan boys. They just don't want to hear anything bad from those games. And if you come with a list of things that are broken / bad in those games, they always come up with the argument that the games are amazing because of the mods (in my opinion, a game should be rated on how it is vanilla). They're just so annoying.

But the opposite of fanboys are also annoying. The ones that just hate on everything they see of a developer. Recently I've encountered a lot of those people while following the upcoming Total War: Warhammer. A little background: Total War Rome 2's release was horrible (this was back in 2013) and people were enraged. Over time though, they fixed the game (which most devs don't even bother with). Obviously people were concerned when Total War: Attila released in the beginning of 2015. The release of that game was much better though (still had some problems). Now with the new game upcoming I see a lot of people just hating on people that say they pre ordered (even in threads that are specifically about those kind of topics), because in their mind, nobody should have faith in CA.
Personally, I hate (literally) those people more then fanboys. If you go out of your way to just hate on people and complain about everything you see and never say anything good about it, you're just a giant dick in my opinion.