There are many companies on the Danube River cruise, basically located on the Pace side of Budapest. The routes of these cruise ships are not much different. There are many shifts during the day and night. I personally recommend the evening one, so that the scenery during the day and night can be enjoyed. The buildings on both sides of the river are brighter at night than during the day. The buildings and bridges on both sides of the river are worth seeing including the Pouda Palace, Fisherman's Castle, Marghash Church, the Hungarian Parliament Building, the Chain Bridge, the Elizabeth Bridge and the Free Bridge.