Budapest is one of the most beautiful cities I have visited. The Danube promenade fortunately is not as crowded as in the banks of Seine (in Paris) and Rhone (in Lyon). Photo enthusiasts will need to stay at least one full day; Budapest is beautiful during day time and more stunning at night. Around 11pm, the lights are turned off.
I plan to go back in the future and discover more places. Hungarians are very hospitable, too!