I need to create a simple windows based GUI for a desktop application that will be downloaded by end users. The application is written in python and will be packaged as an installer or executable. 
The functionality I need is simple - selecting from various lists, showing progress bars, etc. No animations, sprites, or other taxing/exotic things.
Seems there are quite a few options for Python GUI libraries (Tk, QT, wxPython, Gtk, etc). What do you recommend that:

Is easy to learn and maintain
Can be cleanly packaged using py2exe or something similar
Looks nice

[Update] For what it's worth I ended up going with tkinter. It's fairly well documented, can be made to look nice (mainly, use native fonts), and most importantly ships with Python so there's nothing extra to worry about. wxpython also looked good, but the download was 10M or so, and I didn't want to add that extra weight to the packages I distribute.
From using both wxPython and TKinter, I'd say wxPython looks nicer and is easy to learn.
Although you said you are planning on using the program for Windows, it's worth mentioning that I've had problems with TKinter on Mac not working correctly.
Python: Attractive, clean, packagable windows GUI library