Coming to Warsaw, 19.-23.04.

Hey everyone,

I will be coming to Warsaw for a couple of workshops, so I'm using the chance to discover a little bit more of this great city on the weekend from the 19.-21.04.;
Who knows of good bars, cafés (where to have a good breakfast) and any cultural event not to miss out?
I have already done some sight-seeing the first time I was there (unfortunately only for 2 days), so I'm looking rather for the locals insights and recommendations than for the typical touristic attractions...The less commercial, the better.

Thanks in advance, cheers!
Luis