ROOM13 is one of the best places in Warsaw I've ever been at night. You can visit this club not only on Friday or Saturday, but also on Thursday and Sunday, and this is amazing! The bartenders here give really good cocktails, the waitress can always help you with a place to sit and offer you which alcohol you can drink. If you like good music from the best DJs from Poland (but not only!), you should go to ROOM13. Don't wait, check it out!