What is the most important aspect of a metal song to you?
 

Personally, I need good vocals and great guitars to like a metal song.

Guitar riff

Depends on the kind of metal. In doom metal I like a good riff and a good hypnotic groove that everyone locks into. In drone metal I like the texture of the sound. In death metal I like good drumming and unexpected song structure. In black metal I like raw intensity. In thrash I like energy and a tight interplay between the guitars and bass. In none of them do I particularly care about vocals aside from not wanting them to be distracting.

I would have said vocals were very important too, a few years ago, before I discovered (some) death and doom metal, and particularly funeral doom, where the vocals can't really be made out, but it doesn't take from the music. Also pagan and folk metal, and viking metal. I'd say personally yeah, guitar riffs and a good decent melody I can follow.

It's about the guitars to a high degree, but it's quite dependent on the sub-genre for me too. If it's power metal, for example, the vocalist MUST be good. If it's death metal, then the guitar playing will carry the whole load and must be up to the task.
In the end, it's not so different from what I want from other genres, in that I think that good song writing is 50% of the battle won. The other half is performance and production quality/characteristics.

(With songwriting I mean both song structure and vocal/instrumental arrangements.)

Metal's too diverse to point to any one thing, but generally it's the rif***e. But even subgenre to subgenre I might be looking for different things from those riffs. If I'm listening to heavy metal or thrash then give me just plain ol' sick riffs, with something like technical death or thrash metal or black metal I'm going to have more concern for the riffs' textures, or with doom metal then they've got to have atmosphere as well as be heavy and sick.

Atmosphere probably. I need my metal to be either very fanciful, drowning in doom, or sound like it's from another a dimension.

just like everyone else it depends on the genre, but i tend to really enjoy the nastiest stuff. like that kind of black metal that sounds like it was recorded with a tape recorder in the middle of a snowstorm deep in a cavern, that's the ****.

on the other end of the spectrum, there's definitely some metal on the opposite end of spectrum that impresses with beauty and atmosphere.

so one of those two things i suppose.