Try Andrew Bird's "The Mysterious Production of Eggs." Very clever lyrics and lush instrumentation.
Also try John Vanderslice's "Pixel Revolt." Slightly more electronic instrumentation than Andrew Bird, but still great stuff.
Also try The New Pornographers' "Twin Cinema." A.C. Newman and Neko Case contribute excellent lyrics and bright melodies. This one is very poppy, but it's well-crafted enough to avoid being too simple. A.C. Newman's voice also reminds me a lot of that of the lead singer of The Shins (I know you like them).
Also check out Spoon. Any CD would be great. If you want the best-written songs, look for "A Series of Sneaks;" if you want the most polished effort, get "Gimme Fiction;" for the most diverse songwriting, get "Kill the Moonlight."
Also, if you haven't yet checked him out, give Sufjan Stevens a try. His second most recent album, "Michigan," is an understated album of mostly acoustic ballads that express his love for his home state. It's better than it sounds. "Illinois," his most recent outing, is superior in that it features more fully-fledged instrumentation -- we're talking huge string and horn sections, full choruses, the works. He's an incredible talent, and his lyrics are superb. One of the few Christians in indie rock.
All five of those artists are excellent; if I were to gues your two favorites among them, I'd say Andrew Bird and Sufjan Stevens.