Well, I wouldn't know about most of them, but GameGrumps is there chatting away in the reddit comments I believe, so I doubt they're the one. Angry Joe is in the correct "subscriber range" so to speak at just over 2 million, but I don't really think it would be him. As for the rest I just don't watch their channels so I can't really give an opinion on them.

But regardless, so long as the paid review is clearly labeled as being paid for, I wouldn't think any worse of the youtuber whoever it is.