Recommendations for a joystick or gamepad?

If you're going to be playing basic stuff, I can reccomend the Thrustmaster Firestorm 3.

http://us.thrustmaster.com/products/lookproduct.php3?productid=170&skin=Gamepads

It says it's for PC, but I have one and it works perfectly on the Mac. Also, it's only $10. A great buy. (There's also the Firestorm Digital 2, which has more buttons)

I also have the Nostromo N45 Gamepad. I bought it thinking I'd use it for Rayman 3, but when that fell through, it mostly got put in the drawer. It's really nice though. It's great when have friends over so we can play 3 player stuff in Mame or on SNES9x, and others.

It's around $20, but it has buttons out the wazoo and a pair of analog sticks.

I'd suggest getting a cheap playstation control pad on ebay or something (or perhaps you already have one?) and buying a USB -> playstation converter. Mine works wonderfully on my PC and Mac, i use it for all of my games and emulators. You can also buy usb Xbox controller converters, actually pretty much any recent games controller has a usb converter.

IMHO console controllers are much better, both in quality and design. They have to be, they are the only interface to the unit!