A note to everyone:
You can now click on the luminance values. It will lead you to the sources of where I got them (sometimes requiring additional calculation for the maximum value). Some of the linked tests are in German.
Also, there is a new king of luminance, just recently tested by Köf3, the Osram SYNIOS P2720 KW DMLQ31.SG with a 0.5mm2 die. It does up to 316cd/mm2.