Qt Creator is worth mentioning.

Seconded. Qt Creator seems to be a very robust IDE, especially if you're into cross-platform development. The only thing that bugs me about it and I haven't been able to figure out a solution for is the way it handles project sub directories. For example, it will display all .cpp files in a project folder called Source. If you add a .cpp file to the project from a sub directory named "source", it will be displayed in the project file list as Project -> Source -> source -> file.cpp. Same for header or other file types.

My early impressions on a couple others:

Emacs - WAAAAY too many shortcut commands for me. I understand the value in not moving your hands from the keyboard, but my preference for laptops that utilize a pointing stick in the middle of the keyboard pretty much eliminates that as a concern (though I do wish Lenovo would put their left CTRL key where it's supposed to be). Also, default behavior for the TAB key isn't what one might expect.

vi - the dual mode editing mechanic just seems odd to me.