Chrome Developer Tools + Postman.
Intellij Pro, Cygwin with Emacs, Git command line, sometimes SourceTree (though Intellij Git is almost as feature complete).
Tortoise on projects still using Subversion.
Firefox with Firebug, LiveHttpHeaders, and WebDeveloper though more and more Chrome Dev tools.
Usually the standard DB tool depending on database (PGAdmin for Postgres, SqlDeveloper for Oracle, etc.), though Intellij's DB tools are getting 'good enough'.
I'd pay good money for a well developed Emacs keyboard binding for Intellij (similar to Emacs++ for Eclipse)!
http://www.saleonleather.com/product/dark-knight-rises-bane-...
My goal is to be able to interactively develop all languages I may come across with a repl and at least a stepping debugger for when I need it.
I like to keep it all in emacs so I can add tasks to my todo list/agenda with minimal effort (C-c C-r) no matter where I'm at then get back to work without even switching windows.
I do use Xcode, but can't say I enjoy it much. If I could use Emacs more easily within Xcode I would be much happier since I do enjoy the dynamic environment of the Mac OS with ObjC. llvm is pretty good.
Microsoft Visual Studio 2012 IncrediBuild http://www.incredibuild.com
Also web development LAMP, Expression Editor & Visual Studio, and Bluefish text editor
A browser (between Safari, Chrome and FF) if the app is a web-app ... plus tmux + vim (with loads of plugins) + rvm (ruby version manager) + git (github/bitbucket).
Occasionally I might use additional tools to enhance the workflow (growl for notifications, etc.)
Chrome developer tools, git, Atlassian Stash and Confluence.
Cocoa Emacs with Evil-mode, iTerm 2, tmux, Vim for quick edits, git.
iOS/OS X Development: Xcode - Git
IntelliJ with Scala Plugin
Vagrant
Atlassian Stash
After a month or two in Eclipse then switch to IntelliJ for a much faster, smoother, and intuitive GUI and user experience.
That's the path I followed, imho I can't imagine learning Scala in IntelliJ.
Good luck :)