if you don't care for the dude's music then obviously no need to respond, but the guy has a large catalogue of music; atleast in the sense that each album has a completely different feel to it.
Variety in music from a perfectionist if you ask me.

But on the question- i gotta go with Midnight Vultures.
LOVE Modern Guilt & Odelay for close/tied 2nd, but MV is my shit.
And when it comes to mellow/acoustic albums in general, Sea Change is godly.
It's depressing without being whiney, but sounds SO good.