GameCube

Prince of Persia: The Sands of Time

Ok, I just bought it and I want to know even before giving a try: is it better playing with a keyboard/mouse combo or with a PS2-like joypad?

The first one plays equally good with a gamepad and with keyboard+mouse, since the camera rarely takes any odd angles.

Personally, as with most platformers, I prefer a gamepad; and I'd recommend it especially if you plan on playing the sequels, as those play much better with analog sticks. I use a generic "Euro Case"-brand dual-analog pad I bought dirt-cheap a couple years ago and so far it works like a charm on every game I tried it.