Pioneers of the concept album and rock opera, for my money The Who never topped their original outing "The Who Sell Out" and the album cover is the icing on the ludicrously raucus cake.  "Tommy" was a more fully realized magnum opus, "Who's Next" their hardest hitting though thematically incomplete album and "Quadrophenia" the most complex of their grand concept album period.  But "The Who Sellout" pulled off more than the others because it wasn't created under the burden of serious artistic pretentions, unless you call bathing in a tub of baked beans high art.