Here's another best of 2006 writeup, but this deals with my favorite discoveries of the year regardless of when they were originally released.
Running things down by category:
I bought Cuckooland when it came out in 2003 and it was an instant favorite. It's a bit of a tough listen sometimes, with songs about the holocaust, war in the middle east, betrayal by one's friends, nuclear arms, and child abandonment. Shleep is very different, with its swirling layers of pop music. Wyatt's voice is mixed a bit underneath the instruments giving the album a certain pop music sound. The most obviously playful point of the album is "Blues in Bob Minor", which features Wyatt doing a sendup of Bob Dylan's Subterranean Homesick Blues with entirely different music and words, but the song is so distinctive it's readily apparent what the source is. I think that this album is fully streamable in case any subscribers are interested to add it to their tag radio.