If your swear by Fuji's X-Series cameras and you find yourself traveling a lot, their new 35mm lens is definitely something you'll want to pack for your next destination. Their 35mm f/2 (53mm) gives you a versatile lens, silent operation, and and 0.08 second auto-focus. It also has the smallest diameter of their lenses while still offering sharp image quality in a compact package. You also get a weather-resistant build and an f/2 aperture, which should serve you well in low-light scenarios.
$399, B&H Photo