I've used wxpython and pygtk, and have a strong preference for pygtk. wxpython has some advantages: it has better OSX support (widgets look native, and it doesn't require the installation of the Fink x server), and better win32 support (a few gtk widgets, such as menus, don't look quite native on gtk, and multithreading with pygtk on win32 is problematic). But pygtk has better documentation, a MUCH cleaner api, integration with the Glade GUI designer (wxpython has wxglade, but its not in the same league), and a richer widget set. In addition, top itself is in the top tier of free software projects; wxwidgets is not as mature, and its development is not as active.
So, if you're trying to choose between those two, go with wxpython if you need OSX support, or have specific issues with pygtk's win32 support. In all other cases, I'd reccomend pygtk. Greg -- http://mail.python.org/mailman/listinfo/python-list
