The most versatile "normal" range crop lens is the 17-55. It's sharp and fast and minimizes the need for a flash.
My favorite "normal" range lens, crop or full frame, is the 40 f2.8 pancake. Technically, a tad long on crop (like a 64mm on FF), but it's fun to use. Sometimes, the limited, slightly tighter focal length can be liberating in a way. No time wasted at zooming for the best framing, you spend more time on you subject and framing with what you have. (Of course, if it's critical event to cover for someone else, then I use the 17-55 on crop.)