Saw Testament, Megadeth, and Slayer last night (canadian carnage). Was pretty awesome. Testament is my favorite of the 3 bands and they mostly played stuff from their last 2 albums, which was sweet. Megadeth played all of Rust In Peace, then random songs from Endgame and some early stuff, Slayer I don't listen to that often so some songs I didn't recognize, but I think they played all of Seasons In The Abyss and then random favorites.
Testaments set was the best mostly because a lack of security. Security was wayyyy to prominent on the floor for Megadeth and Slayer and I think even at one point during Slayer stopped the pit altogether, which was really fucking gay.