For some unknown reason, many people feel like it's an accomplishment to leave the first comment on a video. Thus, you'll find a "First!" comment on nearly every video, especially if you're among the first viewers.
Nowadays, YouTube only lets you sort comments by the best first or newest first. So even if anyone cared (which they don't), there's really no way to see who was first. If you somehow stumble upon a video with zero comments, resist the temptation to leave this comment. Add something of value instead.
Was This Filmed on a Potato?
You're always sure to find a comment like this on videos of extremely poor quality. Whether it's old and recorded on primitive hardware, or is instead shaky or out of focus, someone always points it out. If you're actually able to record a video with a potato, please let us know.
Is Anyone Else Watching This in 20xx?
Find a popular YouTube video that's been around for years, or a music video of an old song, and you're sure to see this comment. Many others have watched the video this year and will continue to do so for years to come.
Check Out My Channel!
You’ll often see people leave comments on videos asking others to check out their channel. A lot of the time the linked channels aren't anything special. Sometimes these commenters are young kids who say they "don't have a chance" in an attempt to get sympathy. It's difficult to gain a following on YouTube, but you should do so by creating quality content instead of begging for views.
Witty Dislike Comments
Unless the owner disables the function, YouTube lets everyone see how many likes/dislikes a video has. On videos with mostly likes, people will often leave a comment "explaining" why the small number of people disliked the video. For instance, someone might comment "50k people got so hyped that they hit the dislike button by accident".
Quoting the Video
Don't have anything witty to say? Why not just take a quote from the video and paste it as your comment? This is a common sight. Whether it's because people are just lazy or because they want to garner as many pointless thumbs-up ratings as possible, we're not sure.
Anyone Else Here Because of...?
Here's another one you'll see on all sorts of videos. A music track featured in a video game, an original video referenced by a remixer, and similar ones always have comments like this. It's great that you're expanding your horizons like this, but you really don't need to let everyone know how you found the video.
What Did I Just Watch?
Similar to the "I'm in the weird part of YouTube again" comment, this one is another stale response. If the video really was weird, why not talk about what makes it so strange instead of leaving this bland remark?
Your Final Moments
To express how much they love a video, you'll often see people leave a comment like these:
1.best hour of my life.
2.I hope people didn’t die watching this.
3.Doctor: You have one hour to live.
Me: (Opens this video)
I don't know if watching a YouTube video would be in my short list of what to do in my final hours, but I think I'll need a doctor if I see another one of these comments.