Worst Types of Comments on the Internet
This list consists of comments that are not specific in one website (e.g. Who's watching in 2018? is not a contender, since it is only native on YouTube).
Someone always does this: whenever a young woman/girl dies or suffers a serious accident, there are always people joking about their sexual desires towards her (even if they just know her gender, and nothing more about her). It is even more disgusting when the victim is under 18 and the joker is above 40 judging by his profile picture. In addition, they always get 5-10 likes/upvotes, and if somebody tells them not to act like this, they will give a "why r u such a prude loser" reply. It strengthens the toxic masculine stereotypes about men.
That is awful but I have been fortunate enough to not see any such comments. Also I am not exactly sure what to call it but one kind of comment that I have noticed is people who copy and paste the same response to even irrelevant circumstances obviously it is not as bad as some of these things but it is annoying.

What is worse political comments made after a tragedy.
Ex: after someone gets shot a person leaves a comment about how if they had a gun they could have protected themselves or this wouldn't have happened if everyone is allowed to carry guns
To me, it's only bad when they say things like "the victim deserved to die" or make fun of them, and when it's a few days after the tragedy.
Tragedies are something we shouldn't be joking about. Imagine if someone's family member were in the accident.

Anyways, today Senators and the President did some things.
I can't understand why do children make comments like igr and aefrnghojn. They do, because baby shows' YouTube comment sections are full of these.
These comments are just annoying. You being first to a video doesn't mean anything. There is no big cash prize for being first. Stop acting like your sole purpose of existing on this planet is to be the first comment on a random video.
The reason that first comments do not bother me is simple: I can get over them. Maybe an hour passes, and I don't remember them anymore. I just see them, think they're useless, then forget. However, jokes about tragedies, death threats, senseless words stick to my mind severely longer.
Come on, racist, homophobic, Anti-Semitic, offtopic and offensive comments are all worse. In addition, I only see one 'first' comment per month.

Agreed, buying is mean.
No one wants to hear someone use warped logic to trace the cause of a tragedy back to Joe Biden or Donald Trump or whatever. Some people would use anything to defame someone who had nothing to do with this.
Quite common when people are using the internet to help themselves in their homework.
I don't think this is that bad, the problem with text is there is no way to convey the emotion outside of emoji's that are overused and those can be seen as ironic.
The biggest part of a joke is the delivery which can't be done through text unless your one of those that uses asterisks explaining what your doing during the set up and delivery of each joke.
Even if it was a very bad joke, it is still quite annoying when people think it was serious. And if it was a great one, they spoil it.
Seeing someone not get a joke is really annoying, but there's DEFINITELY worse things out there.

On some platforms, it's extremely difficult to tell the difference between troll comments and genuine comments because there are like half of the people who genuinely believe what they say and the other half who are just trolling.
Wow this list is hard to determine, but troll comments have literally no value. At least with political comments and tragedies, there are usually a new, (usually awful), perspective to see a topic.
Troll comments can mean quite a lot. What do you mean?
Example from my list on this site:
List: Top 10 All-Female Metal Bands
Item: Kittie (all-female band)
Comment: "Exceptional live band, Led Zeppelin were exceptional studio and album."
Everything has its haters, but a damn visitor just hated me because I said Justin Bieber is better than (insert music artists)
I never said I like him and someone attacked. This annoys me as hell and in case you didn't know, the comment is here. "Top Ten Most Popular Trends of the 2010s".
Don't like. Don't comment.
Haters gonna hate

Look at the comments under many things that talk about some black person. You're bound to see some racist comments.
These comments doesn't only happen against one ethnicity. Comments insulting whites, hispanics, indians, and arabs occur constantly around the web.
E.g. like here at Comfortably Numb on the best song list. There was a comment saying that it has beautiful lyrics, brilliant solo and vocals, and someone replied: you mean terrible solo, terrible vocals, terrible lyrics?
So people disrespecting others opinions
They don't just happen against gays. People had made homophobic comments as an insult against straight people.
Just as bad as racist, transphobic, and other bigoted comments.

Haven't seen too much of these comments now, fortunately...
A thumbs down is usually less hurting and offensive than the reason behind it, so replying to these comments might make that person even more offended.
Why do I have thumbs down
Anyone who comments stuff like this or makes bots to comment stuff like this needs to spend more than 10 seconds outside.
And the worst thing is that someone from the other side always has to reply and start a war
Comments like these on YouTube are always posted by bots, which always have other bots replying to the comment saying whichever product they are promoting has also helped them. One of the most common scams I've seen in these comments was cryptocurrency.
I have seen quite a few of these recently and it's really annoying.
There are many people who have commented against us. There are some who make fun of our beliefs. They also perceive much of us as homophobes. Very sad.
Bigoted comments in general are bad.
E.g. someone writes Kurt Cobain is a great singer (present tense), I love him! Reply: he died (we never knew that, thanks)