The "Dog Sledding on Mendenhall Glacier via Helicopter" excursion in Juneau from the Regent Seven Seas Mariner cruise ship was one of the best excursions I've ever taken. The helicopter swooped up over the mountains, and the ride from the warm Juneau airport across the green coastal mountains to the icefields and Mendenhall Glacier took only a few minutes. The helicopter floated up and over the mountains, and we marveled at the striking whiteness of the Juneau icefields below. The whole experience was much like an IMAX movie, only we were part of it.
Note that helicopter tours are expensive, and often bad weather can cause cancellations. But, if the weather holds, what a wonderful experience to take home!