My partner and I have cruised on Cunard, NCL, Princess, RC, and Celebrity. The best FOD experience was on a Princess cruise to Mexico-- the meetings were hosted by a very welcoming staff member. However, our last Princess cruise to Hawaii was very disappointing. I honestly don't remember anything about the gay experience on board, only that everything about the cruise felt shabby. I do remember that we vowed never to travel Princess again. We love RC and Celebrity and have always felt very comfortable on both. We particularly enjoyed the transatlantic crossings that we did on RC, our favorite on the Legend of the Seas, one of their smaller ships and one with a loyal staff. We had a table for two every night for 11 days at sea with a staff that we looked forward to seeing every night.
On a side off-topic note, I'm curious about the food on Cunard nowadays. We did a crossing on the QEII in 95 and the food and service was just superb; in fact, those meals remain the best dining experiences I've ever had. We did the same cruise 8 yrs later (in 03), same class, same dining room, and the dining experience was the worst we've ever had on a cruise ship. It was a major disappointment.