[phreezie]

It depends on the effort you want to put in, and the tables you want to play.

VPX has the largest table collection, and the good ones play very well. But there is also Pinball FX which is a lot easier to set up, and they are catching up in terms of cabinet support (we're helping them, the next thing is force feedback support).

There is also Future Pinball which runs a few original games with mods pretty well now, but it's still closed source.