I had to think very long and very hard about this pick, because there are several artists I'm worried I'm about to lose. In the end, I felt these guys, who are a bit more in the current spotlight, offered the highest combination of value and risk to be picked:
The Decemberists.
The Decemberists are a band that I didn't expect a whole lot out of when I first looked into them via iTunes 30-second previews, but they had a cool concept with the Crane Wife series and something that kind of sounded like a sea shanty on the same album, so I gave it a shot. It was SO worth it. They have a very distinctive sound, typically with heavily layered string acoustics, and an even more distinctive lyrical style - some might even say that lyricist and singer Colin Meloy needs to throw away his thesaurus and his OED, but I really love the fact that he doesn't settle for triteness but really sticks his neck out lyrically even if it doesn't always work. Their songs run the gambit from tales of vengeful sailors in the bellies of whales (and your mother who "works" down at the docks), to tragedies about the Civil War, to expositions on Japanese folk tales, and there's almost always something beautiful and antiquarian about it. If you know the band, you're probably mad at me. If you don't, check them out!
Years active: 2000-present
Catalog: 6 studio albums (5h11m), 7 live/EPs + other bonus releases (~3h)
Landmark songs: Here I Dreamt I Was An Architect, 16 Military Wives, The Crane Wife 1, 2 & 3, Yankee Bayonet, Don't Carry It All
Song I keep coming back to: