Singapore Airlines' "Book the Cook" program seems to be the most comprehensive of these services. We've flown Singapore Airlines First Class several times (trip reports here and here) and we've been pleasantly surprised with our "Book the Cook" entrees each time. From what I have read, SQ is offering the service in First, Business, and Premium Economy - so this is an option a lot of passengers not the plane have access to.
|A sampling of First Class Book the Cook offerings|
For our upcoming flight home from Frankfurt to JFK, we selected our meals online from the menu. The hardest part was deciding what to order! I selected the Lobster Thermidor - I had it on a previous flight and it is spectacular.
|Lobster Thermidor SQ Suites SIN - LAX|
You can access the book the cook menu for your flight by logging into your KrisFlyer account, navigating to your booking and clicking on the "select meals" icon on the right hand side of the screen. Menus for departure cities and cabin class can be found online here.