as david says, its a matter of preference and style. each yeast definitely leaves its thumbprint. for a neutral profile, on a american style ale (like the nut brown im conditioning), dry yeast works fine. i like safale ameriavn ale yeast. i always have used white labs, reusing the yesat 3-5 times before throwing it away, but after reading the latest article in BYO about dried yeast i decided to give dry a try. it did fine, completely neutral, with the graains mostly providing the flavor (used on oat stout and nut brown). nottingham is also a good replacement for english ale yeats, not as neutral, with more fruitiness and a pretty nice aproximation of the WL or Wyeast english ale. but for other styles, definitely go with liquid, as the yeast profile is needed by the style (as david said, belgians are teh best example).