Coda or CSS Edit

[ombrenelcielo]

That's good:

Owners of only Espresso: if you purchased Espresso on or after 10 April 2009, you get a free upgrade. Otherwise, you will qualify for the regular Espresso upgrade discount.

 

[rufhausen]

Regardless of what you choose as an editor, I'd take a look at LESS and/or Compass/SASS (links below) if you are getting serious about CSS. Coda, at least, will allow you to associate .less or .scss files with the CSS syntax mode. I'm not sure about other apps.

http://lesscss.org/
http://compass-style.org/