You might not think Warsaw as a vibrant, party city, but you just have to know where to look. Bars and clubs are usually open till the last person leaves. Polish vodka and beer pack quite a punch, thus you should drink at a steady pace. Only cash is accepted. #1 on your list is Kolska 2/4 for drinks till you drop.
If your feet can still keep up, there’s a host of clubs in Warsaw that will be happy to welcome you like Lemon Klub, Zoo, Ground Zero, Club Extravanganza and M25. From the sound of these, you’re sure to have a fantastic time.