Although I like a couple Death Cab for Cutie songs, overall I find their music to be bland and predictable.
If you're looking for a homogeneous sound, they have that in spades, from phrase to phrase, song to song, album to album. Being this formulaic has brought them a surprising amount of success and popularity, however, so I suppose it serves their bank accounts quite well.
Personally, I'd prefer if the lead singer, Ben Gibbard, would invest more time in my favorite side project of his: The Postal Service.