So the topic of Gwar came up in the chat, and that lead to the following question: "What metal albums from the last decade would you consider a masterpiece". I had one immediate answer, but then had to think a bit. I'm not sure I can fairly answer the question, except to just list some of my own personal favorite albums from the last decade or so that I think are examples of bands who are just killing it in a nearly flawless way:
Linking single tracks because I think linking the entire album is a bit overkill... You can look if you're interested:
Katatonia - Night Is The New Day (2009):
Katatonia is one of my favorite bands, but most of their albums are not what I'd call "great". They have a lot of standout tracks and a lot of tracks that I tend to skip. Night Is The New Day is one of their more recent albums that I consider to be right up there among my all-time favorite albums, and I listen to it a hell of a lot, and can just put it on and let it go and thoroughly enjoy it in its entirety. The only track I consider kinda weak is the very first one.
Madder Mortem - Eight Ways (2009):
You'll notice a trend in most of my favorites in that I like stuff with at least a little prog or jazz influence going on. I've got some exceptions, but most of my favorites are doing something more technical than just verse / chorus / verse and driving beats. I find that I can zone out and let it play in the background, but I can also really focus on it and get fully absorbed when it's doing something more complex. A lot of my favorite music is doing this, not just metal stuff.
Opeth - Sorceress (2016):
These guys were insanely heavy melodic death metal with a twist of jazz about 15 years ago, but their stuff from the last decade has evolved into a more pure prog-rock sort of sound. I wasn't a fan of some of the earlier of their prog-style albums, but Sorceress is fucking fantastic, and is easily on par with the best of their death metal stuff in terms of how listenable the entire album is.
Callisto - Providence (2009):
I'm gonna be honest and say that their previous album 'Noir' is probably the most 'friendly' of their albums thus far. Their first album, True Nature Unfolds, is extremely heavy and has lots of atonal shit going on in it. Providence is the other end of the spectrum and is way more jazz / prog than metal. It's arguable whether this should even be considered 'metal' at this point, but they're another of my all-time favorite bands. Very slow on new material, tho.
So that's a good start, I guess. I'll add some more later, maybe. This isn't really 'traditional' heavy metal, tho. This is mostly melodic / prog type stuff. I don't listen to much heavy metal / power metal / etc.