I haven't voted in the GMAC in a while but honestly, what's the deal with Blind Guardian? Everything I've heard from them sounds sort of atonal or boring.
Atonal? No idea what you've listened to so far, but they started out as Speed Metal and have become the metal version of Queen.
Valhalla is one of their classics, it's from the second album and particularly in live settings you'll see the audience sing the chorus for minutes after the song has ended.
They have a bunch of acoustic ballads and The Bard's Song is one of them. Another live staple.
Mirror Mirror is the first of their songs I've ever heard and it's part of their Nightfall In Middle Earth album, a concept album about the Silmarillion. You'll notice that the further into their discography you go the higher the amount of vocal and guitar tracks present on their songs. Also, this album (as well as a song called Lord Of The Rings on their third album) released well before the movies; Hansi (the vocalist, lyricist and on the first 4 albums bassist) is a huge fantasy fan and most of their songs are based on some kind of book.
I've skipped a lot of great songs but I'm trying to share their most representative material over their career. And Then There Was Silence is about Homer's Iliad and an epic in every sense of the word. The song has literally over a hundred guitar and vocal tracks and is an entire journey.
On their 2010 and 2015 album's they've worked with a real choir and orchestra on some of their songs. This is one of them and it was written for the video game Sacred 2 (where the band appears as NPCs playing the song, IIRC).
There's a ton of great music that I didn't mention, but I think that's a good entry point. Feel free to skip around and see if anything catches your attention. Their earlier material is rather straight forward and melodic, though as they got older the songs got more and more progressive, never leaving the Power Metal framework though. Give 'em a try, maybe you'll like what you hear.