Every year I (usually GL also) go to Download Fest at Donnington, UK (the old Monsters of Rock site) and have rarely had a dull moment there.
Here is the link to the site after the first 9 bands have been announced and there are still over 100 bands to follow, 2 of which are headliners.
www.downloadfestival.co.uk
I'm already imagining being in that field in the middle of nowhere rocking out to Back in Black :)