Welcome mboston. I would say that Regent ranks up there with the best of the best. Regent uses smaller ships and you can get up close and personal, unlike the bigger ships. There is also free and reduced shore excursions in Alaska this year which is HUGE for this area as the excursions are very $$$$. I am taking advantage of the good rates and going for a second time this September.
The only other cruise line that I would consider would be Silversea but I am not sure if they are doing Alaska this season?