Last weekend I had a discussion over who is the best one album band.  

For such a debate it is vital to set parameters.  It has to be a band, which rules out Jeff Buckley.  Lack of a second album due to death doesn't count either, which rules out Jeff Buckley.  Their name must not begin with J, which rules out Jesus Jones.  As does their multi album catalogue.  As does using the word 'best' in reference to them.

Days on, my original answer remains. I therefore present Burning Benches by Morning Runner from their sole album Wilderness Is Paradise Now, released in 2006.