Some great suggestions in here...let me add some more.
If you like Black Sabbath...(if? IF?)...don't forget Heaven & Hell, which is essentially the Dio lineup of Sab under a new name.
Tony Iommi has 2 solo albums, the first of which, Iommi, features him using the same formula Carlos Santana did for a couple of albums (and Slash is doing right now): get a bunch of stellar guest vocalists to sing different tracks on your album.
(Really, its hard to go wrong exploring the Dio/Ozzy/Black Sabbath/Deep Purple/Iommi/Blackmore band tree...)
Given the subject matter, you probably can't go wrong with any of the shredders from the 1980's forward: YJM, Impelliteri, Chastain, MacAlpine and so forth...especially those who preferred instrumental music.
Early Scorpions is especially good for this kind of fun. Check out the classic "Sails of Charon": [ame=http://www.youtube.com/watch?v=nDNXCIQyd04]YouTube - SCORPIONS [ SAILS OF CHARON ] PROMO-VIDEO.[/ame]
Then there is Krokus. They had a series of singles that explored quasi-fantasy/sci-fi themes (think John Carter of Mars/Road Warrior-ish), starting with "Screaming in the Night" from the Headhunter album:
[ame=http://www.youtube.com/watch?v=OPJND0fl0-A]YouTube - Krokus-Screaming In The Night[/ame]
Hard rock supergroup Blue Murder had a couple of epic tunes- like "Ptolemy"- that had a nice feel to them.
King Diamond had some interesting albums. I used to own Them and Abigail, but I eventually sold them.
The German band Helloween has some nice horror-esque songs and blazing guitar. Check out "Keeper of the 7 Keys". [ame=http://www.youtube.com/watch?v=niIIwVStGok]YouTube - Helloween - Keeper of the Seven Keys (Part 1 of 2)[/ame]
If you like the Zep knock-off bands, check out Bonham (featuring Bonzo's kid), Fastway (featuring Fast Eddie Clark of Motorhead fame) and Katmandu (featuring Fastway's original vocalist).
Metal Church's early work would be to your liking, like "Watch the Children Play" and "Metal Church."
And of course, where would this thread be without bands like Earth or Sunn.
Buckethead, Bootsy Collins and Bill Laswell have done some interesting metal/industrial/funk/world beat fusion work under the band names of Material and Praxis. Bootsy's project, Zillatron, mined similar metal fusion on the album "Lord of the Harvest."
[ame="http://www.youtube.com/watch?v=O4ku_24KAaU"]YouTube- Zillatron ( Bootsy Collins ) - Count Zero[/ame]
And I'd be remiss if I failed to mention the one and only Meshuggah song I like, "Bleed," which has Far Realms adventuring written all over it...
[ame="http://www.youtube.com/watch?v=qc98u-eGzlc"]YouTube- MESHUGGAH - Bleed[/ame]
Less obvious choices would be the solo work of Alex Skolnick (Testament/Savatage/TransSiberian Orchestra)- he has some jazz and jazz fusion versions of metal tunes; Rodrigo y Gabriella with their flamenco fusion versions of metal tunes; Apocalyptica who do chamber fusion interpretations of metal tunes. Really a headwarper for someone expecting metal to hear these reworked tunes.
I could go on...