<p>I would like to to try Emacs, and want to give it the best chance possible.</p>

<p>To do this, it seems like having a good <code>.emacs</code> file is important.</p>

<p>I primarily use Mac OS X (so I have looked at Aquamacs), and I mainly do Python programming, so anything specifically for that would be great.</p>

The most important configuration change that I have found is not one for your .emacs, but for your OS.  In the "Keyboard & Mouse" system preferences, in the "Keyboard" tab, click "Modifier Keys..." at the bottom and then change "Caps Lock" to behave like "Control."  Then train yourself to use the caps lock key (to the left of the "A") instead of the control key down in the corner.  This will make the whole experience both far more productive and far more comfortable.
see:
Emacs on Mac OS X Leopard key bindings