I use QtCreator.
It's well designed, stable, and has good intellisense, syntax highlighting, project management, built-in GUI WYSIWYG editor, is multi-pane-able, built-in debugger support (GDB - though GDB has bugged out on me), built-in source-control support for a dozen source-control tools, and is cross-platform.
The reason I don't use Visual Studio (and never have, so I can't compare it) is because I'm developing for cross-platform, and I want a cross-platform IDE to reduce my confusion. QtCreator seems to be the best non-VisualStudio IDE I've found.
It can be used with and without the Qt GUI api, so don't let the name fool you.