I'm an avid metal fan I like anything metal. I do specialize in Power Metal it is what I live from I don't think I could pass the day without listening to at least one song. My library is made up of over 150 hours of only power metal. Maybe you haven't heard of Power Metal before? That's Normal because it is mostly more popular in Europe, South America and Québec. Power Metal is a mix of traditional Heavy Metal, Speed Metal and the energy of Trash Metal often with symphonic elements. When I first started to listen to it I heard a lot of times that it was metal for geeks, I often denied for some unknown reason, now that I think about it, really it could be metal for geeks.
Power Metal often utilize over dubbing the vocalist voice to make this epic feel to the song this also includes choirs, in some bands they even have have an opera vocalist. Heavy use of keyboards and often symphonic instruments even sometimes using a full symphony like Fairyland, Dark Moor and Rhapsody.
First observation, a lot of the power metal band utilize Dungeons and Dragons like themes for their lyrics, artwork, style. The most obvious case of this is Rhapsody Of Fire, they are truly inspired by dungeons and dragons even getting the artist of D&D to make the cover art of their albums. My personal favorite is their new album Triumph or Agony shown below. Power Metal is often about concepts and Rhapsody concept is the Emerald Sword saga, which is and epic story which spans withing five CDs. Some continue the story while some might go in deeper into a character either the protagonist or the atagonist. They do end the Emerald Sword saga with the album called "Power of the Dragonflame" but they quickly start up a new story named "The Dark Secrets". Before I didn't see how it was all so cheesy but it is and I love it so.
Another band guilty of this style is Blind Guardian one the pionners of Power Metal, they don't venture into the D&D realm but they do go pretty damn close into the J.J.R Tolkien realm. They don;t only go into J.J.R they also go into Frank Herbert, Peter Straub, Stephen King, Michael Moorcock and more. Still their biggest influence is J.J.R Tolkien you can see that since their first album. They really blew things out of proportions with something never really been done before. In 1998 they released Nightfall On Middle Earth and it was and still is epic, acclaimed by critics and fans, it features 22 tracks not only songs but narrations between to tell the story.Blind Guardian and Rhapsody utilize other media to influence them but some band create their own world and story. Like for example Helloween's Keeper of the Seven Keys, Dragonland's Dragonland (Hyper cheesy) and one of my personal favorites Iced Earth's Something Wicked This Way Comes. Now I know what you are saying but Something Wicked isn't from Ray Bradbury or Shakespear it is and original story. Other groups how utlize the still medievil stylings of valour, honour, comradeship and hope like Hammerfall and Flaconer each song cheesier than the next. Still the cheesiest lyrical theme I ever heard is Alestrom's Captain Morgan's Revenge. A mix of folk pirate music and metal with some of the cheesiest lyrics known to man.
Another geeky thing I realize is Iced Earth's "The Dark Saga". This is yet another concept album based or entirely taken from the comic book series Spawn even Todd McFarlane (the creator of Spawn) did the artwork for the album cover. Symphony X also comes to mind with their album "The Odyssey" a musical transition for the epic poem featuring a 25 minute long song.
Often Power Metal is stereotyped be being about wizards and elves while that might be true it sometimes goes beyond that like for instance Gamma Ray has their album "Somewhere out in Space" which is a futuristic outer space story, dealing with frequent Gamma Ray theme of freedom. There's also Primal Fear and their album Black Sun another album about an outer space adventure. Still cheesy but a different way of cheese.
In all I wouln't call it geek metal, I would call it cheese metal. I mean it is so cheesy yet I love so much I don't know why. I could get you into even more cheesy material like those Viking bands or those pure metal symphonic bands with 5 vocalists with a total of 12 members, but for now I'll restrain myself.