Revisiting this subject area I think I have to go for Obscured by Clouds, I am not a fan of the closer Absolutely Curtains but apart from that it's a very solid record with some excellent material - Burning Bridges and Mudmen are both classic Floyd with Wright's organ and Gilmour's guitars shining, The Gold It's In The... isn't very deep lyrically but has a strong Gilmour guitar workout to make up for this, while Roger Waters' Free Four uses an unusually catchy tune to sweeten some rather morbid lyrics about death.
Come to think of it, death and ageing seem to be a theme of the Obscured By Clouds - look again at the lyrics of Childhood's End, Wot's Uh The Deal and Stay as well as Free Four, giving it some solid thematic ground and fitting the laid back music.
More I think has some terrific material, particularly early on in the album - Cirrus Minor is a good opener, Ibiza Bar and especially The Nile Song both rock (the latter being the closest Floyd ever came to heavy metal) and Cymbaline is a quality composition with some excellent and thoughtful lyrics - see 'apprehension creeping like a tube train up your spine'. However, the latter half is let down by some mediocre instrumentals. I do dig More Blues, but Quicksilver doesn't justify its seven minute length.