Definitely a once in a life time experience. I have done the picnic tour to the Grand Canyon in March when the weather is perfect. Not too hot or too cold. I went first thing in the morning bc I was told it is the best time. You fly out looking at the sun rising & as you land down inside the Grand Canyon & sitting on picnic tables on bluff eating your breakfast drinking mimosas the sun is rising over the top of the Grand Canyon. Such a beautiful site.
I have also done the night time city lights tour of the strip. It was really cool to see all of the lights from up above.