Text editors are like sports teams; everyone has their favorite. There isn't a right or wrong text editor to use with Sass. However, using one that supports the Sass syntax will obviously be beneficial as it will provide lovely syntax highlighting that makes the files easier to work with.
Thankfully, most quality text editors either support Sass syntax out of the box or have third-party plugins that extend the functionality to include syntax highlighting for Sass. At the time of writing this, my current text editing application of choice is Sublime Text (cross platform, available at http://sublimetext.com), although programs like Coda 2 (OS X only, available at http://panic.com/coda), Espresso 2 (OS X only, available at http://macrabbit.com), and Aptana (cross platform, available at http://aptana.com) also have native support for Sass.
