While I wouldn’t say that the Atari controller is particularly ergonomic, it’s a classic of the form and brings back all sorts of happy, fuzzy memories. This $25 controller connects to a Mac or PC via USB and supports all major game emulators including Stella and MAME. You can even pop it open and hack in two new buttons, just in case.
ThinkGeek notes:
Warning: These USB joysticks do not connect to classic Atari hardware. They’re USB. USB wasn’t even invented until 1996!