Honour and Blood from Tank has one of my favorite metal album covers, although I dislike the logo and wish they chose a flatter typeface.
Here are some metal covers I like, although these aren't necessarily my favorite records.
I don't even mind ones that look amateurish at all as long as they look rad.
Not a Voivod fan, but I always loved that first one. I never saw the second, but that looks pretty cool too.