Often they add background music and it's bad for two reasons:
1) cheap sounding free licence music
2) often runs the entire video without changing. Videos over 5 minutes long listening to the same track? Torturous.
‘IM ROD DILLWEED AND I’M GOING TO EXPLAIN TO YOU FROM MY BEDROOM DECORATED WITH ACTION FIGURES AND MOVIE POSTERS FROM INSIDE MY MOM’S HOUSE WHY THE LATEST SUMMER BLOCKBUSTER IS WOKE BULLSHIT, BUT FIRST LIKE AND SUBSCRIBE, I TRULY HAVE NOTHING ELSE GOING ON, I CANNOT FIND A WOMAN NOR FULL TIME EMPLOYMENT, I’M EXTREMELY SOCIALLY AWKWARD AND THE NEIGHBORS THINK I’M WEIRD FOR YELLING ABOUT MOVIES ALL DAY.’
And I dislike:"IF YOU GUYS AGREE WITH ME, HIT ME UP IN THE COMMENTS AND LET ME KNOW WHAT YOU THINK". Then you look at the comments, and they didn't respond to any of them.
1. Overly long intros where they introduce themselves, deliver some corny tag line, encourage us to Like and Subscribe....
I don't care about you. I don't know if your content is worthy of a Like and Subscribe yet. Let me see what you got first, then I'll decide. I usually skip past the first ten percent of the video as a start to get through this crap.
2. Not so much anymore, but there was a time when the video would be some screen cap video of the creator opening Notepad, then goddam TYPING the solution to a problem. Complete with freakin' typos which they would then backspace and correct. Jeezus, what a stupid idea.
There are probably others that I can't think about right now.
I HATE #1. One example is a demonstration video (e.g., an exercise) and the intro is as long, or longer, than the darn demonstration. Also, some people should rehearse the damn thing so that they don't say "you know" or otherwise repeat themselves in their already overly long intro. Another peeve is overly long title cards in an intro. A title card that takes three seconds to read but appears on the screen for ten seconds.