This is #1. I don't care if you are one of those idiots who think the black album through Reload and Death Magnetic are bad, because they aren't. Lulu and St. Anger, worst metal albums ever. But you have to think of their creation of the genre, their mainstream success, and how every music fan and human being knows them
Anthrax definitely is a curious bur freakin' awesome band, the speciality is speed metal, but in the first two albums they do a lot for thrash metal and make a works basic for groove metal, rap metal and alternative metal
Metallica's second guitarist Kirk Hammett was in this band before joining Metallica. Bonded by Blood alone is what makes them one of the best thrash metal bands. And also Blood in Blood Out.
The greatest metal band from Germany. They were not only a thrash metal band but also the first album had early death metal vibes. 80's and early 90's as well as the 2000's albums are amazing.