Best place in my experience is on a Kenai Fjords boat trip of at least 6 hours but now I only go on the long 9+ hour one.

My preference is definately in the wild but they are on exhibit at the Sea Life Center in Seward with underwater viewing. I have also taken trips to St. Lazaria Island out of Sitka- a puffin rookery with excellent views. Otherwise it is going to be a gamble. I have seen them fly by in Glacier Bay- but if not taking a tour, sightings will be chancy at best and with binoculars you will have a 10 second view.

Another part of the country has the best tour I have ever been on- out of Jonesport, Me. with Norton's. Walking among the puffins, standing in blinds with them right outside.