David Lynch is said to have a fond love for the city. He even bought a defunct power plant (in which I actually spent the night.)
An inhabitant has called it, "The City of Sex and Business," but I found this to not really be the case. Apparently it has quite a lot of business, but it is still dwarfed by Warszawa.
Of the two times I've been there, I've been to the decrepit power station and to several museums. One was the old concentration camp. Much smaller than most would think of, it used to be an old factory. Another was called the White Factory, part art museum and part factory model where they display machines used in the textile business. An old palace built by a textile baron was very interesting.