SET 18, I had the feeling you weren't after aviation related sites necessarily. Here's a few of my favourites;
If you're a movie fan, you'll already know about <a href="http://www.imdb.com" target="_blank">www.imdb.com</a> , the one site apart from Pprune I'd insist on for the desert island.
For the real truth about those incredible stories you hear, <a href="http://www.snopes.com" target="_blank">www.snopes.com</a> or <a href="http://www.urbanlegends.com" target="_blank">www.urbanlegends.com</a>
For music, <a href="http://www.allmusic.com" target="_blank">www.allmusic.com</a>
<a href="http://www.biography.com" target="_blank">www.biography.com</a> for, well, you guessed it!
<a href="http://www.tvgohome.com" target="_blank">www.tvgohome.com</a> for an offbeat satirical look at TV.
<a href="http://www.theonion.com" target="_blank">www.theonion.com</a> for the best satirical site on the net.
<a href="http://www.dictionary.com" target="_blank">www.dictionary.com</a> for English usage
and <a href="http://www.libraryspot.com" target="_blank">www.libraryspot.com</a> provides a heap of information about all sorts of things; one of those sites you can spend hours in, if you like that sort of thing of course!