Airline food is, for the most part, an afterthought. No one boards a flight expecting a culinary experience, but some airlines serve better food than others. In fact, sometimes that food is downright delicious. Inflightfeed is a blog dedicated to reviewing all the different meals offered on 150 different airlines around the world. The blog's creator, Nik Loukas, takes the time to sample and review all of his airline meals, some of which look pretty fancy. This is useful if you're flying with that airline and looking for a decent meal, but even better, the site has a database of airline food info that offers details on a number of different carriers. You'll get info on pricing, menus, special meals and what kind of offerings you can expect, depending on your flight.
You can look up your specific airline here, or head to the blog below and browse the reviews.