A truly outrageous party or gathering. To recieve this moniker, the experience should of transcended the norm and in fact gone way beyond it - to realms that are (almost) void of defintion. The happiness, love and sheer exuberance of it all should of reminded everyone in attendance the joy of what is to be alive. Off the hook is as close as we've got thus far to describe such an event. Use sparingly.
"How was your weekend Jim?"
"Jesus, fucking Christ, it was insane, completely and utterly off hook!"
"Oh, very well. I need those insurance reports on my desk first thing!"