There are a few excellent restaurants in Juneau. You should consider dungeness crab in any of these ports however. It is without doubt a far better crab than any of the other species.It is more tender and sweeter and even the body cavity meat is amazing. Good things come in somewhat smaller packages, or so it seems to me. A big meaty dungeness cannot be beat.
If you're stuck on king crab, try Tracy's King Crab Shack. It's a def local favorite.