Hands down for me are flights, with always doing at least 2-3 every trip. From the air is the only way to really see the vastness of Alaska. I have taken well over 100 Alaska tours and these continue to always be breathtaking.
As only my opinion, I never recommmend independent visitors booking the Tundra Wilderness tour, but always the shuttle to at least Fish Creek. Those extra 10 miles are significant for bear habitat and the shuttle 1/3 the cost.