5 most influential albums, for two metal guitar legends.

I think the first guitarist that mainly influenced the development of hard rock, and after heavy metal, was Jimi Hendrix. I know that probably this sounds too old, but he gave rock the big push.
Also, Dimebag Darrell from Pantera, and Quorthon from Bathory were very importand for the development of thrash metal, black metal, viking, and many posterior kinds of metal.
And, of course, Iron Maiden influenced the way guitars started to play since the very first years of the 80's decade, as well as the aesthetics and the lyrics of heavy metal.
Regarding the visual dimension and aesthetics in terms of clothes, it was Judas Priest who created the main points.
 
I think Tom Schultz (Boston) really gets left off of these "lists" too often. While Boston was far from metal, that huge guitar tone he created was a big influence on many guitarists, myself included. I still can listen to the old Boston stuff and am just as amazed at his tone today as I was back in the day.

Bryant