Middle eastern airlines that are fantastic (Emirates, Qatar, etc) the food is mediocre. Any airline I’ve flown out of Japan, Qatar or UAE, Korea, France, and surprisingly London have been good. Turkey is also good, but it’s because it’s Turkish Air.
I think the Seattle based flights for Delta are better than SLC or LAX. ATL can be hit or miss for Delta flights. JFK is probably my least favorite when flying Delta.