WWW - Somebody could say it is hip hop but it is not. Like they say, it is experimental/electro/rap. I hope you can enjoy the oppressive atmosphere even if you can not understand the lyrics.
Flamengo - 70s czech underground band; the important album is called Kure v hodinkach (Chicken in a Clock).
Moimir Papalescu & The Nihilists - Maybe the most interresing contemporary czech band playing sonmething like mature electroclash. You can here a lot of you know, from Prodigy through Nick Cave to Sex Pistols.
MIDI Lidi - it is a three member minimal electro band with vocals
Hrdinové nové fronty - also called HNF, the only one czech GOTHIC PUNK band slightly influenced by Oi, active from 1985 to 1990. The chime of their amazingly rattly guitar and the frontman's voice is absolutely charming!!