Luggage on line have nice list of "50 of the best travel sites you probably never heard of". My favourite on the list has always been the Airline Meals site. I love this site - it is like a cross between food porn and trainspotting. Thousands of photographs and reviews of airline meals from the best in the world like SQ first class to the What The Hell Is That of Borat's favourite Air Kazakhstan.
The fantastic underground site not mentioned is SeatGuru - do not fly without looking here first. Shows you the layout of each of the major configurations of each of the major airlines - which seats to look for and which to avoid. Green for good, yellow for something to note and red for reach for the sleeping tablets. Even SeatGuru can't help you if you are flying Qantas to the US code sharing with American as you will end up on a MD S-80 aircraft, which as you can see here has nothing in Business Class that is recommended. Not a seat.
Thanks to Mark Fridgen's blog where I first saw the link to the 50 best.