John Peel had a really good knack of summing up bands brilliantly in one line for example:
The Fall - "Always different, always the same"
The Smiths - "Uniquely for the period, bore no clear evidence from other musicians"
I also remember David Stubbs of Melody Maker describing New Order's presence at an AIDS benefit as appropriate because of their "emaciated hi-NRG".
Any other examples?