Sorry if this gets long.
Haha, well this is difficult, but you can consider the album(s) I like as either 1 album, 2 albums, or 4 albums, but I'll refer to them as 1 split into disks and themes, since it's all in the same project by the band.
Thrice - The Alchemy Index. It's a concept album consisting of the basic elements; fire, water, air, earth. Each EP's music is themed after each elements. It's very various in music, and yet is perfect in the style/genres each disk thrives in.
Fire is mostly post-hardcore hard rock
Water is mostly electronica and post rock
Air is mostly indie rock
Earth is mostly acoustic/folk/bluegrass
It's brilliant.