been playing for 5 years, but i really suck for someone playing that long. consider me beginner intermediate.

what are some popular thrash/heavy metal classics that i can learn the whole song that arent too difficult?

i know all of war pigs except the solo
i know all of one except the last solo
im learning master of puppets

If you've been playing that long, and don't feel like you're as good as you should be, practice more. Or take lessons. That's really all there is to it.