I think half of the appeal of space shuttles to me lies in the fact that they do look just like passenger planes -- except bigger and therefore more awesome. I have always been of the Executor school of thought in terms of Most Awesome Star Wars ships: the more Star Destroyer, the better (insert your own size queen joke here). Similarly, 747s are my favorite airplane. And in fact I can admit to having looked at airplane porn of the modified 747 that carries the space shuttle (whilst thinking "YO DAWG" in all caps).
From Wikipedia. OMG awesome.
But in addition to my own totally platonic feelings about huge airplanes, the space shuttles are just all around amazing. And I'm very sad to be seeing them go. So if you haven't had a chance yet, enjoy watching the video of the shuttle launch and reading about how amazing these craft really are.