Viera's videos are great. Dont always agree with his opinions (especially on 80s Kiss), but the reviews are entertaining nonetheless. I also discovered a guy called Rageaholic. He mostly reviews video games, but he also has a series called "Metal Mythos" where he's done retrospectives on Queen, Judas Priest, Darkthrone, Danzig, Yngwie, Motorhead, and Dokken. He's VERY opinionated, but if you can look past that, theyre definitely worth checking out. Here's the Queen one (though i'd reccomend turning it off before the adam lambert rant at the end):
https://www.youtube.com/watch?v=dY_mc7jU29k