Go to places for czech style lagers is:
U Supa - Its in the middel of prague, nearly as a tourist trap - Tho a very well made Czech Svetly - Herbal, Smoot , loads of vauge baugette to it, very true to style and a very good example.
T-Tanker - At the top of shopping mall - Not really a beer geek places but 8 taps with sometimes good Czech lagers!
Vinohdrasky Loaced in Vinohrady - Very very tastsy and clean Svetly and Polotmavy - Good place for eating as well. Close to Beergeek - which is guess you know. Loads of American brews Ipas, apa and stuff like that.
Strahov - Close to the monstary on top of the city - Nice View and a killer Polotmavy and Tmavy.
Lokal - Just to try a fresh pilsner Urquell from tank, the date on tank is often only 1-3 days old.
Dno Pytle - Sometimes fresh francionen lagers also fresh czech style lagers. U Medvidku 50m from there good svetly.
U tri Ruzi - Again in city center, very good polotmavy and Svetly.
Zly Casy - Both American, European, and lots of classic CZ style, served in good condition.
NaPalme in prauge 9 i think. Good Lagers on tap Uneticke and others. Close by is a brewery called Pivorar Kolcavka - Very good lagers
Jihomedsky in Prauge 11 which is kinda far - Good Svetly and Polotmavy
There is loads more, ask me if you wanna know more, this is just a few of the highlights.