It also has the only cubist lamppost in the world (in Jungmanovo Náměstí). The advice for the evenings is always to get a couple of streets of the main parts, cheaper and more authentic. Get yourselves up Petřín tower for a great view of Prague and the largest stadium in the world (
http://www.prague.net/stadion-strahov), but get the funicular up there, we didn't and it is a hell of a walk.
And Dazzza is right about Budepest, top place, but Hungarian beer is chuffing awful. Another Dreher? No thanks...