1Some guys listen to an entire song with no facial or body expression which makes me wonder why they called it a "reaction" video when there's no reaction to what they hear/see
2Some guys listen to an entire song without saying a word or making a sound
3Some guys listen to an entire song without pausing to verbally react to a moment in the song
4Fake "first time listening" reaction videos
5Some guys talk too long about things not related to the video (their problems, politics, dad, girlfriend, and so on)
6Instead of making comments on the song, they try to figure out what the song is about when there's info on the Internet
7Some guys focus on insignificant elements in a song section missing the real gems in that song section
8Some guys don't bother to find the version with the best quality available (sound quality and video quality)
9Lazy and crappy reaction videos about masterpieces are particularly annoying
10Many reaction videos show no effort or any valuable content
11Pausing the video every 5 seconds
12"This bar/chorus is fire". Then why did you pause half way into it to tell us?
13Low video quality; no one wants to watch an out of sync reaction you filmed on an old Nokia.
14When they don't even react and just talk about something in their life
15Not truly understanding the song context and just sitting there grinning and smiling, not listening to the lyrics while rocking to the beat of the song, and the song is actually sad or reflective.
16Having loud donation alerts
17Some guys who stay like statues when watching the video
18Bopping their head to a slow song
19Fake reactions of black people to white singers
20They're all fake and you know it, but you watch these charlatans anyway
21There's a tiny screen for the artist while you can see the reactor's whole room