I am weaker on the Czech stuff than other east Euro stuff, but I still have a bunch filed and love it.
Some scattered, incomplete thoughts written in a hurry.
The beat stuff is quite strong. The Matadors and George & Beatovens records are really nice. Petr Spaleny (he's done stuff with Atlantis) has a record he did with Apollobeat that's pretty underrated that I really dig. It's called "Zvon ????lenc??v" and gets called the East Euro Sgt. Pepper a lot. Lots of beat girls like Eva Pilarova, Hana Ulrichova, Marta Kubisova, too. Olympic started out as a beat band and their LP "Ptak Rosomak" is cool. Later stuff went hard rock, and past the early 70s, I'd stay away, as they became poop, but the early stuff is rad. Marta Kubisova's stuff with the Golden Kids is super rad too. C&K Vocal put out a record called "Generace" that is just awesome, and includes a Czech cover of a long Marek Grechuta & Anawa psych track. It's like... I dunno, vocal prog or something. Hard to describe and really great.
Radim Hladik and Blue Effekt/Modry Efekt stuff is great, starting out beaty and moving more into proggier/rocking realms.
Collegium Musicum is more classical-influenced prog, but it's quite great and rocking, and I find it a lot more listenable than a lot of bands from other parts of the world that went that way.
There was a lot of blue-eyed soul stuff like Framus Five and Marie Rottrova/Flamingo that was nice too. Quite often informed by blues-rock and psych/beat ever so slightly.
Jazzrock was great too, but I think people covered this already. Jazz-Q, Mahagon, Fermata, Energit and others. There's a great comp called "Jazzrockova Dilna" with a sculpture of a head on a green background that is worth getting.
It gets deeper, I'm still learning. A record hunting trip into the Czech Republic is due soon. Apologies for lack of Czech diacritics. I am lazy, tired and don't speak Czech.