I can't agree on The Clash, if someone said play mean album that defines punk it would be the first Clash album "The Clash"...I think that London Calling is an OK album subject to too much hyperbole (ditto Petsounds as someone already mentioned) and then I think that they have enough decent other tracks from various other albums or singles (eg Stay Free, WMIHP, Clash City Rockers, Radio Clash)...I guess if you don't like punk then you won't like early Clash stuff