^ not to be nit-picky, but Imaginary Sonicscape was released in 2001, not 2003.
43. Sigh - Hail Horror Hail - (1997)

This to me was Sigh's first 100% masterpiece. Infidel Art may have been quite experimental, but if you don't count the EP entitled Ghastly Funeral Theatre released months before Hail Horror Hail, then Hail Horror Hail would clearly be Sigh's real Avant-garde breakthrough. This album is excellent from start to finish, and maintains a great atmosphere while showcasing a lot of variety. You have more rocking songs like the title track, also, scary, intense, atmospheric songs like 12 Souls, experimental songs with strong/prevalent outer-genre influence like Invitation to Die, crazy fast, brutal rockers like Curse of Izanagi, and epic, doomy, amazingness like Seed of Eternity. This album is a must for any really big fan of Sigh, along with pretty much every other album of theirs, but most fundamentally Imaginary Sonicscape, and In Somniphobia. This album really is like "a horror movie without the pictures" in the best possibly imaginable way.