A bit off-topic, but one great polish writer/journalist that deserves to be more known is Kapuściński. His style mixes journalistic objectivity with fiction in a brilliant way.
I'll pipe up for another, the dazzlingly imaginative Bruno Schulz. His work is half an evocation of his family's life in a small early 20th-century Polish city, and half cosmic and out-there. He's like a Polish Kafka, but more whimsical, less austere. He haunts his own writing like a ghost because of his shocking death and the fact that his major work was lost. This adds poignancy to reading him that wouldn't otherwise be there, like a painting that was damaged in a way that became part of the art and made it a different whole.
Two other Polish modernists that I've been meaning for years to read are Gombrowicz (Ferdydurke) and Witkiewicz (Insatiability). Both are said to be fabulous.
Gombrowicz is a genius. It's nice to see him mentioned since we just had a Borges thread, and the two were the greatest living authors in Argentina for years.
There's a recent translation of Ferdydurke that's supposed to be good. Be careful not to get the earlier translation, which was translated indirectly from a French intermediate and really doesn't have much to do with the original as a result.
Gombrowicz was a genius, indeed, and I cannot recommend his books strongly enough. However, honestly, I think that a good translation of his books is something extremely hard to do, and I am not too sure if possible at all. For me a hugely important aspect of his writings is a creative attitude to the Polish language, he was playing with it (and at times, forgive me, taking a piss of it) like no one else. I just cannot imagine how this can be translated to a different language. But it's not the only aspect of his works and I believe his dramas were successful not only in Poland.
Gombrowicz's diaries are a classic of contemporary literature and testament to the man's genius (and temperament!). Strongly recommended to anyone who wants an ambitious, but rewarding read.
Well, I would strongly agree with the Kapuściński recommendation, but while we're going off-topic with great Polish writers, let me suggest that readers re-visit Joseph Conrad.
Re-reading Heart of Darkness as an adult was a totally different experience from the forced read of it as a child.
I also really enjoyed Conrad's Nostromo, a true masterpiece.
http://en.wikipedia.org/wiki/Ryszard_Kapu%C5%9Bci%C5%84ski
His most known book:
http://en.wikipedia.org/wiki/The_Emperor_(book)