Eclipse for any project that's an excessive amount of Java, which at this point is only Android apps.
XCode for any project that's an excessive amount of Objective-C, so just iOS or OS X apps.
Visual Studio / MonoDevelop for anything that's going to be published to a Microsoft environment (Windows, Windows Phone, Xbox, or Unity cross-platform development).
Sublime Text 2 with Vintage mode for everything else.
I'd love to just use one editor for everything, but the language IDEs (Eclipse, XCode, Visual Studio) are too good in terms of intellisense and platform integration to pass up for their respective languages. It's a pain in the ass juggling contexts, especially with vastly different keybinds in various editors, but it's definitely worth the pain when you're on a roll with something.