Prune an Airliners for the pictures, are the only two sites I visit. And one other based in the US, ATCmonitor.net, it's atlantas ATC corridor, Macey 2 arrival, with radar screen and radio, worth a look for any spotter.
By the way, I have been on Prune since it was a bullitin board post website. I kept on loosing my passwaords. And I love this site. Lots of fun.