Gryphon had one of the more extreme changes between their debut and second LPs, with the first largely given over to traditional folk tunes, though admittedly far from traditional arrangements.  Done to often hilarious effect, especially in Estampie, where the bassoon player slips in riffs from Chattanooga Choo Choo, Somewhere Over the Rainbow, and the main riff from Cream’s Politician.  The Devil and the Farmer’s Wife is one of the funnier things put to record, with its voice characterizations of the Devil and the Little Devils, the varied guitar treatments, and the hilariously out-of-place Maple Leaf Rag riff at the end.

RQTG3 is, as noted by others in this thread, is an astonishing album.  In its own way, I think it equals King Crimson’s best work in its contrasts of quiet, pastoral moments to ones more driving and rhythmic.

Midnight Mushrumps I’ve found a bit harder to get close to but it has its great moments too.

Raindance may actually be my favorite, though it has shorter tracks (except for the epic Ein Klein Heldenleben).  The title track is one of the more evocative instrumentals I’ve ever heard, and its effortless segue into the Beatles’ Mother Nature’s Son gets me every time.

Treason I very recently bought, and my immediate impression was that it sounds like a whole other band recorded it (which is partially true) but not awful by any means.