I have used Eclipse+PyDev in the past. I don't use the debugger though and don't find the outline all that useful, so now I just use the PythonWin interface that comes with the ActiveState Python distribution.
Another one that I've heard lots of people seem to like is Stani's Python Editor (SPE). You can find it at http://stani.be/python/spe/blog/ -- http://mail.python.org/mailman/listinfo/python-list
