That's the bees knees!
Never before was I able to articulate my feelings of overwhelming awesome and sweetness. And it's expandable too. While "It's the bees knees!" will work well for most situations of kickass, "That's the fucking bees knees!" or "That is so the bees fucking knees!" or even "That is so the mother fucking bees mother fucking knees so much those bees never had their knees so fucking much as right this god damn second."