Well our first ever cruise was to Alaska in September 1999 and we had no intentions of doing any other ( We just wanted to see Alaska). We have been 'hooked' ever since 
We LOVE Alaska and have booked our 4th trip for next May all on Celebrity :grin
We personally like a balcony when cruising Alaska but this is just our choice. We like to sit on our balcony and watch the views and relax with a cup of tea ! :grin
(There are plenty of places on board the ship that you can see the wonderful views and relax though.)
We have been in May and September and enjoyed both 'seasons' which were differant. There was more ice and snowcaps in May, very pretty.
As for the land trip our first trip to Alaska was Vancouver to Seward and we hired a SUV in Anchorage for 3 days and we drove to Denali etc on our own and had a great time at half the price the cruise lines charge. We stayed at the same Princess Lodges the cruiseline stays. There are lot s of other places to stay at up there
( We haven't done the Dome Traim ride from Fairbanks .)
We have taken the Train ride from Anchorage to Seward and that was wonderful
As for excursions there are so many. Do you know what your itinerary is yet? Have you any thoughts on what you would like to see or do?
I know people here have done a variety of tours so I know you will get some good help and advice
Have a great cruise!
