I use the Incase Terra Sleeve with mine and it works well. I made a short video review of it if you're interested; http://www.youtube.com/watch?v=Tni2tiHt_N4
I have a 15 inch green version of this... http://www.futureshop.ca/en-CA/prod...spx?path=11a4744c227b9d45837db78a8c069662en02
I use this: http://store.apple.com/us/product/HA175ZM/A/incase-15-neoprene-pro-sleeve-for-macbook-pro-with-retina-display?fnode=50 Designed for the rMBP and its a custom snug fit. Even with my Incipio case it still sits in nicely.
Speck & Waterfield I use a clear Speck that has the hard shiny surface versus Satin surface. I then use a sleeve designed by Waterfied Designs of San Francisco. check out the WF website. http://www.sfbags.com/products/macbookair-cases/macbookair-cases.php