well not really my favorite, honestly i've only used very few ide's and so far code::blocks seems to be the fastest and easiest to use and for me is just right for a student ( since my pc is crap and i don't like to waste my bandwidth downloading a 600MB iso )
I personally use QtCreator. The Qt development tools and inclusion of signals/slots in code completion are quite nice, it's quite lightweight, its UI is simple and intuitive, and it has a nice extensible architecture.
I'm kind of irregular when it comes to IDE's for a while I was a QtCreator fanboy than i switched to Eclipse and now I use sublime ( I know it's not an IDE ). Honestly I'm thinking of switching back to Qt because I use a netbook and Eclipse is too heavy.
Qt Creator is what I'd call a medium-weight IDE. It's really not that heavy at all, but it's not super-light either.
It's really not that difficult to design GUIs in it. The graphical GUI editor can take care of most of the code generation for you, but there's always the option to dive in and chance things yourself in a subclass from the generated code that it provides.
And yes, it's pretty easy to understand, but more advanced options are there if you want to play with them.