I was always intrigued by the painting featured on the cover of Laszlo Krasznahorkai's The Melancholy of Resistance (one of my favourite novels, if that is not obvious) but didn't know anything about the painting.
Some googling showed me that it is a detail from a painting called "Christ's Entry into Brussels in 1889" by Belgian painter James Ensor (1860-1949)
I found two articles which have more background on the painting - here and here. Very clever and interesting choice for the cover I must say.
(Click to enlarge)