The most fun I had was my first fight against atheon. I had no idea what was going on and was completely unfamiliar with the map, I hadn't even watched a youtube video. It was a week after vog was released. My buddy had me on portal duty with him, so we ran to the back of the room to get teleported. He'd grab relic, I'd run around lost shooting oracles, then when we'd leave to go damage atheon, and I'd run off a ledge. Every. Single. Time. Different ones each time. One of the people we picked up off the tracker just kept laughing. It was an embarrassing amount of fun.