Bucharest has no tourism infrastructure at all, so any visitors should pre-plan their itinerary.  The Parliamentary Palace is un-missable and definitely worth a visit, although tour guides can really alternate between the best and the worst.  Not far away is Strada Lipscani, the heart of the historic district.  The Romanian National History Museum suffers from an absence of exhibits but the Peasant Museum and the Village Museum have really excellent displays on traditional Romanian life.  Finally, there are many beautiful parks in the otherwise grey city, and Cismigiu Park and Herastrau Park are both not to be missed!