Well there is an expression you could use: "have the time of your life". e.g. I had the time of my life at that live concert yesterday. "have the time of one's life" = means to enjoy oneself more than ever before. http://idioms.thefreedictionary.com/have+the+time+of+life

Yes you can use this expression

you can also say that it was the best day of your life=)