Bucharest is at once grim but uplifting. Like everywhere you go in Romania there is a huge amount needing fixing but it is interesting to see a country with so much opportunity to improve. I felt reasonably safe wandering around the city with my GMT II and it is clear that up until WW2 the architecture was impressive with a strong French influence. For a hundred yards you really could be in Paris, then you turn the corner and face an appalling concrete pile constructed after the 70s earthquake.
The greatest entertainment is probably the traffic and working out how pensioners manage to consistently cross 8 lanes of it unscathed; hiring your own car would be completely mad. The most depressing part is the volume of stray dogs, they cope with the traffic too.
Public transport is difficult and the Metro doesn't seem to go where you want to, i always took taxis.
The highlight is always going to be the Parliament/Palace complex breathakingly large and mad but my favourite is the Village Museum (Salatuni); a park with houses from all over Romania. Apparently they were brought there to help workers moving to Bucharest remember home. There is a "old town" with some decent looking restaurants i'm sure others can make specific recommendations.
A couple of days is enough is Bucharest, if you have more time get out to the Mountains, Sinaia is close and has a fairytale castle. Romanian railways are cheap and arrrive, but not always on time.
Thinking about Romania makes me quite sad, seeing a country that presents so much opportunity convinced me that the EU is wonderful project.