I just got back from Europe yesterday, and Prague was one of my stops. We only had two days there, but just walk around and you'll find plenty of classical art and music. In addition, there are plenty of good restaurants and pastry shops. The airport has plenty of foreign airplanes, but most are Western, with only a few Russian. Also, most of the foreign airplanes are from nearby countries, and few are heavies. About the only heavies you can find there are the two Czech A310's, OK
-WAA and OK
-WAB, the first of which I was on from Prague to New York yesterday. Airport police tends to be friendly to spotters there, so you shouldn't have a problem.
If you'd like to see old Russian airplanes, go to Budapest (about 480 km) and see Malev's outdoor aviation museum. They have an An-2, Il-14, Il-18, Li-2, Tu-134, Tu-154, and Yak-40.