Currently listening to the full version of Jiyuu no Tsubasa by Linked Horizon.
Apparently, the composer responsible for this theme (and its predecessor, Guren no Yumiya) is well known for writing songs that are actually more suites as opposed to songs (which explains why the full version of aforementioned Guren no Yumiya sounds like two different songs that have fuck all to do with each other, mashed together). Jiyuu no Tsubasa however, sounds a lot more coherent. It actually sounds like the sort of song I'd expect from, say, Avantasia. Except in Japanese. With occasional bits of growling in German which sound like the guy hit himself on the head and thought he was Rammstein.
While TV-sized-versions while I find Guren no Yumiya better, full version wise, Jiyuu no Tsubasa wins by a long shot.
Tl;dr, I may dislike Attack on Titan greatly but holy shit do I love its theme songs.