I attended Soundwave '14 which was the first show I'd ever been to (as I was 15 at the time and metal shows are normally 18+). While there, I saw Amon Amarth, Mastodon, Devildriver, Trivium, Five Finger Death Punch, Testament, Gwar, Volbeat, and Tesseract, as well as a bunch of miscellaneous bands on other stages while walking around.
I saw Megadeth in 2015 when they toured with Children of Bodom. I mainly went for CoB, but Megadeth was grouse too. Unfortunately, both myself and the person I was with were both minors, so we were stuck in the seated section
I also saw Eluvetie in 2016, with a local band called Stormtide as an opener, which was the best live act I had ever seen. A few hundred people crammed into 170 Russel for a few hours, only mere weeks before three members of the band left.
Since then, I've mainly seen a bunch of local Melbourne/Geelong bands (mostly death metal, black metal, and one thrash show).
I've seen Dragon (famous for their song Rain- google it!
) live and that's about it- I'm keeping an eye out on my favourite artists to see when they're touring though! 
ayyyy april sun in cuba