Qt is too heavy for OpenGL work unless you are building an editor or something otherwise very GUI focused.
As mentioned, GLEW is not a GUI library but as it's name suggests an extension loader. You'll want to use it (or one of these http://www.opengl.org/wiki/OpenGL_Loading_Library) for any desktop platform (Win/Mac/Linux) work, so keep it around.
GLFW is still IMO a little too GLUT-like, that is to say convenient at first restricting in the long run. That's fine for experimental or demo code though which seems to be what you're doing?
SDL & SFML are similar beasts with SFML having a nice C++ API, a little higher level abstraction with more features and a little less tested with fewer supported platforms vs SDL having a nice C API, being a little thinner abstraction, having a few less features, being more widely tested and supported on more platforms.
I generally recommend SDL as a platform abstraction layer (if not needing drawing functionality) due to better platform support, testing and it's corporate backing, but SFML has a particularly friendly, helpful and engaged community if that's a consideration.
Edited by xenobrain, 14 July 2014 - 06:39 PM.