If you want any sort of sky watching activity.  If that star gazing, sun or moon rising, the best place is definitely at the summit of Haleakala.  The views from up there with the scenery and the whole mystic power of the place definitely puts you into a trance that you will not forget.

The sunrise comes up from beyond the crater and you are transported into another world.   The view and the experience can not be fully explained and the photos do not do it justice.   It’s an experience that you may grumble a bit about because of the time it takes to get up the mountain and the hour at which you need to get up to do it.  The grumbling and pain of that will be long forgotten while the vision will stay clear in your memories for a lifetime.

The sunset from up on the mountain is pretty speculator too.  You can see from below that the sun sets a bit later up on the mountain then down at the beach in Kihei.  If I am going to enjoy a sunset at the beach, then being in Kihei is the place year around.  Otherwise, my choice is definitely up on the mountain where I can see the transition to night happening far below in the towns of Kahului, Wailuku and Kihei.

Check out this sunrise / sunset tool.