After having an account on YouTube from 2009 until 2012, it's very interesting to look back on a lot of these fads that had happened (and continue to happen) on the website.
I used to watch a lot of YTPs when I first joined, and I believe during that time that was when stuff like ear rape and the like was really catching on. I even remember making some myself before I eventually lost interest in YTP itself since I felt like every YTP was just distorting everything to where it was nothing but ear raping audio and flashing colors (I was always a fan of YTPs that had hilarious sentence mixing and some sort of humorous storyline to it). Though I will admit those Spongebob Poops by people like LinkOnDrugs are so crazy; they take the show and make it to where it almost borderlines on creepypastas, and the editing and sentence mixing is just amazing. It's very surprising that YTP has lasted for over ten years now; it feels like almost yesterday that people were just making clip shows out of the Zelda CD-i games. Occasionally, I'll watch a few YTP videos, but it requires some digging to find the good ones.
Rants and commentaries were also one my favorite trends back the day. As many people in this thread pointed out, a lot of these people come across as spergy and miniature versions of A-Log in retrospect. Not to mention everybody back then would always do a rant on tired old topics like "YOUTUBE FUCKING SUCKS BECAUSE GOOGLE", Fred (back when he was still a thing), Chris Chan, and whoever was essentially the Lolcow of the Month at the time. Every now and then is there a rant that's actually interesting.
On the subject of commentaries, they were entertaining until the commentary community began to circle jerk each other, make unnecessary commentaries upon commentaries on rants because somebody didn't agree with the original commentator's points, proceed to make a video going "BANDWAGONS HAPPEN BECAUSE X, Y, AND Z!!", then rinse and repeat with another person of interest. I remember seeing one video get like five commentaries stacked onto each other, it was THAT bad. Pretty much after BlackBusterCritic starting doing videos on them did people like RandomDCE and youngbloodfantasy91 fade into obscurity.
Also, any video that has characters from Sonic X acting like Family Guy and Spongebob characters is the stupidest shit I've ever seen. Like this for example:
Actually, anything that has to do with Sonic X is absolute shit. Plain and simple.