Definitely do Captain Larry's Orca Whale watching in Juneau. Also, take the bus out to Mendenhal Glacier and go to the viewing area to look for the bears. The K2 avaition flights in Talkeetna are great as well. My dogsledding trip in Skagway was fogged out, which was a major disapointment. We also did the fly over the Arctic Circle optional tour in Fairbanks where we visited the village of Weisman-it was really interesting!!!
Have a great time in Alaska. It's like nowhere else.