Tales From Topographic Oceans, the ultimate one track a side , a double album with just 4 tracks
If you have a spare 83 minutes, enjoy (probably not the right word I hear you say)
Should really be another thread, 'Albums with one great side and one poor side' I would include Mickey Jupp's Juppanese. Side 1 which has Rockpile supporting Mickey is far superior to side 2