My favorite Czech Beer is http://www.pilsner-urquell.cz/cs/.
Beer has 12°. This beer costs from approximately from 30 Czk .

Next Czech beer which is popular in Czech Republic is Gambrinus.
Beer has 10°. This beer you can buy in pub from 20 Czk.

More information about Czech Beer you can find in this article.

Which Czech Beer you prefer and Why ?