For a JK?
I recently upgraded to The kit from Rebel Off Road. Includes drilled & slotted rotors and improved pads. From what I remember, made in America, not the crap you find on eBay. I haven't tested to prove their claims of a 40% increase in stopping power, but I can say they were incredibly easy to install, have performed great from day one, and the customer service was beyond top-notch. Those guys responded to each call, email, or PM with no delays. Delivery was quick and well packaged.
More expensive than buying new, but less expensive than a full caliper upgrade. If this sounds like an add, that's because they did such a great job...