I believe that I should win the DA 50mm prime because I love taking photos of the little details here and there on cars that other people might miss, and I shoot a lot handheld in low-light conditions, so the f/1.8 would be very useful for my purposes. I also love bokeh, and who doesn't love a good bokehlicious picture? While I have a bit of experience shooting with different cameras, the K-5 II is not only my first Pentax camera, but before I got the K-5 II and the 18-135mm WR, I have never had the opportunity to shoot with anything that wasn't a decidedly sub-par kit lens (sorry Sony and Canon, your kit lenses honestly aren't that good at all), and even now I've never even been able to try a prime lens. Some would consider that a photographer crime, so take that as you will.
(In the interests of full disclosure, the image below HAS been post-processed, but only with the default DxO Optics Pro 9 filters, and the correction module for the K-5 II and DA 18-135mm lens)