Not Czech, but I really liked Schlenkerla Fastenbier. Imagine that amazing smokey smell of a fancy butchery and then imagine the beer tastes like that.
http://beeradvocate.com/beer/profile/263/21704
For a cheaper, day to day lunch beer, I liked Svijany.
http://www.pivovarsvijany.cz/
-A Seasonal BISim QA guy