Just reading this thread makes me glad I don't fly very often! I would be hard pressed to think of a really bad meal I have had on a plane in 50 odd years of flying. Most meals I must have coped with and suffered no ill effects.
I would have to say that in recent times, I have not had a bad meal on Singapore Airlines in business and economy. It is airline food, but has mostly been tasty and edible and some were even enjoyable.
My experiences of Qatar business Berlin to Singapore, and also of Virgin Australia Business to LAX and back were also more than satisfactory.
I remember the days when QF was a real airline, and the food was tasty - even in cattle class. Mind you, that was a long time ago. They used to do nice breakfasts of scrambled egg, and Canadian style bacon. I managed to fly QF first class a few times in the 1970's. Sadly I watched the food and service decline over a short few years.
Air Asia X food I don't even bother with. Take some snacks and keep them discreetly hidden. I can do an eight hour flight without a meal. Just have a good breakfast and a nice meal later in KL.
US airlines like PanAm, AA, and Delta used to be great back in the good old days also. I remember an ice cream sundae on Delta that was to die for.
My pet peeves, the half size muesli bar you get for a snack now on Virgin. The flight to Sydney takes longer than it did 20 years ago, and back then they managed to serve and clear a hot meal for the entire plane without any problems! How does that work? Other peeves, the rock hard ice cream that has been mentioned, the cold rock hard bread rolls, and the unopenable plastic cups of water or orange juice, especially when you are confined in cattle class.
I am flying PE QF Mel -Sin in October - my first trip on QF in about 20 years I think. I am not looking forward to it at all. But I am flying PE on Singapore Sin-CDG two days later so that will erase any bad memories of the QF flight.