The Inn Above Tide is the highest-rated hotel in Sausalito, and is located right on the water with fabulous views. "Luxury" means different things to different people but I find the hotel to be classy and high-end.
Like Ann, I have not heard of it (or any other hotel) being "THE place" in the Bay Area, and in addition to helping in the Sausalito forum here I also edit the largest online guide to Sausalito.
Ann and I usually agree when we respond to questions (she has a very impressive knowledge of the area), but I do want to sound a cautionary note on Cavallo Point. Please do a thorough Google search and read not only the TripAdvisor feedback but that on other sites before booking a room there.
Unlike Inn Above Tide, which has exceptionally consistent high feedback scores, Cavallo Point gets a mixed range of ratings on various online sites.
Other highly rated local hotels (if you want to save a little money over Inn Above Tide) are The Gables Inn and Hotel Sausalito, both in the heart of downtown Sausalito.
The positive side of Cavallo Point Lodge:
Located in the middle of a national park
Many rooms have views of the Golden Gate Bridge
Restaurant has a Michelin star and is a gourmet dining magnet
They have been ironing out some of the rough spots from their first year of operation
The negative side:
The less expensive rooms sometimes are up stairways in older buildings with no elevators and do not have the great expansive views
A good room may cost as much or more as Inn Above Tide once you factor everything in
No room service (Yes, amazing!)
The restaurant is very expensive
You have to drive to get anywhere else to buy aspirin, get a less expensive meal, etc. (but to some that's a positive, not a negative!)
Hope this helps!