"Best" depends on what you want to see. I've been twice-the first time my son was only 7. We used Anchorage as a base for some of it, visiting the musk ox farm, reindeer farm, the Alaska Native Heritage center, and browsing through shops in the city, took the train up to Talkeetna, and drove down to Seward. There we stayed on Fox Island and visited the Alaska Sea Life center. Second trip my son was 17. We spent 4 days on Afognak Island (no camping there) fishing every day, about 5 days on Kodiak Island exploring, and a few days in Anchorage horseback riding and just slumming. Next trip will be going to Denali and maybe Fairbanks or over to Juneau. "Best" is too general a term to give a good answer to.