I have always admired the American heavy metal band Metallica.
They are very talented, but I don't like their individual personalities. Great group, though
I feel you on that. Metallica has been around since 1981 when Lars Ulrich and James Hetfield got together. It says something when a band lasts that long.
Yes it does. The original guitarist went on to form Megadeth
Metallica is also known as one of the "big four" in the trash metal scene. 
What are the other three?
Alongside Metallica, you have Slayer, Megadeath, and Anthrax. These bands were known for their fast tempos and aggressive musicianship.