If you still want the Tsim Sha Tsui neighborhood without staying in Chungking Mansions, Mirador Mansions is a couple of blocks north of it on Nathan Rd. It's basically Chungking very lite, but the location is still good.

My least favorite part of that area, besides the smoking, is the presence of touts- offering watches, food, rooms, and later in the day, drugs- so I always walk on streets parallel to Nathan Rd.