Worst Business Class for me was TransAtlantic SAS Copenhagen to Seattle in a "Sleeper Seat" which was an additional US$600. The plane was old and rickety. The food was bad. The flight attendants were surly. The cabin was huge and crowded.
For first class, Air France gets my vote for CDG-SFO. Their featured meal was ground veal "a l"Alpo" (my description. The glassware came in one shape, two sizes no matter whether for water, champagne, beer, or juice. At least the FAs were very friendly contrary to their reputation.
Long live LH & SQ in First!
Nobbi