Metal is one of if not the most diverse genres. It's got extremes in every category, and this makes being a fan of metal sort of difficult to qualify, since most people like *some* metal, but hate others.
It helps to articulate the elements of metal that you enjoy, then ask for those particular things. Or even better, rule out the ones that you don't like.
Preferences might include:
- Technical play (dreamtheatre) vs. simplicity (static X)
- Singing (dragonforce) vs growling (cannibal corpse) vs. screaming (suicide silence)
- Theatrics style (slipknot vs. cradle of filth vs. devin townsend project)
- Fast (dragonforce) vs. moderate (parkway drive) vs. really slow (doom and sludge metal)
- Genre influences
- Linearity (is it close to heavy rock, or is it math metal?)
- Dense (strapping young lad) vs. 'thin' sounding (lacuna coil?)
- Do you have a preferred gender of vocalist?
- Is it even important to have a vocalist?
- How novel a sound are you after?
- Are there themes that you are not interested in (satanism, gore, rape for example)
- Do you care about how hardcore the music you listen to makes you seem? (There are some bands that are taboo if this is the case)
So once you know what you prefer, choose what things are valued, acceptable, and unacceptable. Then people can give you rundowns easily
For example, I find almost everything acceptable, though get bored by too much growling in anything that's invariably slow. Most popular metal bands are a little linear, so I've got a pretty strong preference for newer more progressive or extreme sounds. Theatrics doesn't matter too much, but it's a little disengaging if they take those theatrics too seriously. I don't mind the gender or even existence of the singer, but can't stand specific vocal styles such as those of Mic Patton, Rody Walker, and most power metal and Nu metal vocalists, for differing reasons.
I guess the problem with just asking open endedly is that most people that enjoy metal are just waiting to palm off their highly specific pet group, which is rarely helpful for people just generally getting into it, since a lot of it comes across too severe. You listed bands you already know you like, so that's a pretty decent place to start.
I'd recommend: