Software in C++

Question

what is the best & efficient way to make an application with nice User interface in C++

Answer 1

for the old school stuff, look for dosbox turbo CPP

Answer 2

I use Qt, it is a complete programming environment.
Very rich and cross platform library.
It do have a GUI designer, and it is also mapped to python "PyQt" (if you are going to use python later on)

There is also MFC which works with windows only.
It is also very rich, easy to bypass and go straight to the Win32 API when you need it.