I tend to write SCSS and use Sass via Grunt or Gulp. Lately, I've been adding Autoprefixer via PostCSS as a Grunt or Gulp task so I don't have to think about where/when to add prefixes cause I feel pretty strongly that those shouldn't be in your source.
To keep things from getting too crazy, I use SublimeLinter and scss-lint.
Other than that, nothing else has really stuck.
Atom has a pretty nice linter plugin as well :)
Have Atom's speeds improved? When I tried it out late last year, it was significantly slower in opening files than Sublime Text :-/
Wow wasn't expecting that many. Might be nice to get a summary of the default stack for different types of projects: web site, app, mobile, etc..
Judging that cover photo.