What's the best controller for "Steam games" in general? I've seen a consensus on the Xbox Windows controller, but how compatible is it with most games? Say I bought Binding of Isaac, would I be able to play that with that controller? I really dislike keyboard and mouse setups.
Far more compatible than any other controller. It really is, with no exaggeration, the defacto PC gaming controller. If a developer programs controller support, 99% chance it's designed around 360 Windows controller driver and layout.