I only had one music studio require a take down.  Which sucked, because it was one of my favorite videos that I put together.  But again, I don't own the content, I just mash it together.  Since I can only claim ownership to the entire work and not to the parts I used to create the videos, I don't feel I have a complaint.  If someone took the video I created and subsequently used it in whole, I would be pissed.  If someone who held the copyright to one of the works I used in my video did, I wouldn't be pissed but honored that they felt it was worth publishing as their own.

I think AVGN would fall under "fair use." Like how companies reviewing a video game don't have to pay for rights to put game footage in a video review.

No. VG Chartz and every other gaming website would be closed... Plus countless other people. AVGN, Zero Puncuation etc. for example.

It is a bit ridiculous if companies were going after people such as the AVGN (perhaps they're afraid of their game being in the 'shitty game' category), but what about ones who LP games? There are arguments that this promotes the game, and gets people interested. On the other hand, some argue that the LPer finishing the game actually loses sales because people have seen what the ending has to offer.

Personally, I think it's a bit stupid, since I watch a few games that NintendoCapriSun has LPed, and I've ended up buying a few titles because of it (even games that are old still get some Virtual Console loving. Even though I completed Mystic Quest a long time ago, the LP motivated me to play through it again).

I like LPs because it provides point of references for almost any game worth referencing (and quite a few that aren't). So if i need to pull a reference to "that one bossfight in The Last Story," say, then it probably exists.

Fair use allows for bits of copyright content to be used for the purpose of critique. All those "Let's Plays" aren't reviewing anything. It's no different than running a ripped movie on youtube.

If you want to do a legitimate review there is a legal way to do it. But if all you are doing is uploading long videos of games, movies, etc. then you are breaking the law.

In some sense, you are still missing some elements of a game with an LP, unlike posted music. The gameplay is still an important element, otherwise you're not getting the "full experience" of the game.

Besides, what about LPers who provide other things during the gameplay, like some comedy or anecdotes? Is this any different from A show that plays music in the background of their news story?

Well only youtubers in America gets paid

Who decides which is or isn't "fair use"?

You can't post an entire movie with your own commentary, without license from the content owner. Mystery Science Theater 3000 used public domain movies or they paid for the right to use a movie. You can't use someone else's content, add your own stuff on top, and them publish it to the web for everyone to watch.

A show that plays music in the background of their news story paid for that music.