I stuck with Tkinter combined with PMW for a very long time, but the lack of extra widgets finally drove me to look elsewhere.
I tried PyQT but didn't have a good experience. I can't remember details, but things just seemed to have little "gotchas" - which the mailing list were very helpful with sorting out, but I found it frustrating to keep asking for help over little items of unexpected behaviour. I have not tried PyGTK so cannot comment. I finally decided on wxPython - with my basis of Tkinter (graysons book) it was quite easy to pick up and run with. The wxPython book is quite good and helps get started and using it. I would suggest if you buy and read that, then you will no longer find wxPython difficult to get started with. -- https://mail.python.org/mailman/listinfo/python-list
