I have been in Budapest not long ago and had such a good time with my friends there. To be honest I didn't even know this city is so cool until I have visited. We had a nightlife tour guide there and got some fun activities arranged for us too.
We have visited the baths what was such an awesome relax and detox as they say.
We were at Szechenyi which has outdoor and indoor pools, steam, hothothot saunas, ice cold and thermal pools... amazing
You can find some tips and tricks here about Budapest: http://www.hungaryforfun.com/tips-tricks
And as it is I am highly recommend for having the best time in town to check these guys out:
It is a smart idea to have a nightlife tour on the first night and on the followings you would know the city well and where to go. 7th district is cool, but so many bars hard to choose.
Anyway, hope I was able to help and aim you to the right direction.