I'd also have to nominate Dark Side of the Moon just because it's so classic, and the countless not-so-sober hours we spent watching it with Fantasia. It's definitely up there in my book.
Vulgar display of power . Changed my perception of music , I remember having to buy it on cassette as I did not have a cd player in my car , it did not leave the tape machine for about a year ! Seems like only yesterday and it was 18 years ago
Helloween Keeper of The Seven Keys 1 and 2
Gamma Ray land of the free
Judas Priest Stained Class
Iron Maiden Somewhere in Time, Seventh Son of a Seventh Son
Opeth Blackwater Park
Smashing Pumpkins - Siamese Dream - I got this album at a time when I was going through a bad period of depression, and I just loved every song so much, so its one of my favourite albums I'll always have in my collection haha.
BUT
If we are talking actual epic albums, then - Nevermore - This Godless Endeavor, its so fucking epic