Some years ago we combined a trip on the "Rocky Mountaineer" with an Alaskan cruise. Disappointing overall - a freight derailment meant we had to take the bus replacement for the RM and the cruise ship was a cross between Maplins Holiday camp and the Pride of Dover cross channel ferry.
However, the Alaskan scenery is spectacular and I did earn the Whitepass and Yukon teeshirt. MP makes Alaska look most attractive but the Indian narrow gauge and some of the South American steam tours are ahead on the list, if I could ever persuade Mrs 2750.