For me, for the Heavy Metal look, I think I'd have to go with:

Damned
Never Surrender Freedom
Made of Scars
Diamonds and Rust
Atomic Hell

Maybe even Tears as well, but I suppose it would depend on what album cover it was for if it was to be used for Heavy Metal, and the others might fit as well.  BTW, don't knock your talent as an artist, art is the overall image the observer sees, and if it looks good to the observer, then it's good.  Kinda like what (I believe) Vangelis once said about music "If it sounds good, it is good."  -  I think you can basically translate that to "If it looks good, it is good."  ;-)

If it's any consolation, I see the Heavy Metal look in your art without you even asking, I'm very fond of that art myself, I think the album art that goes with Metal albums in general is absolutely amazing, like a mass of nice, gritty detail in super-deep colour.