Interesting can mean different things to each of us. As I pondered this questions, my first thought was about uniqueness of the building rather than the location. So many properties look the same. For example, not much distinguishes most CYs or FFIs. That's not to say there aren't interesting CYs or FFIs. I'd say the CY in Ocean City, MD is unlike any other of the brand. (I still don't think it's a category 9 property ).
Many hotels along the highway are so similar that if you took the signs away, I would be hard pressed to identify them and not just Marriott properties either (three stories, beige colored, entrance in the middle. It could be almost anything).
I've thought of a few interesting properties. Not all are in fabulous locations, though some are. I enjoyed the boat launch on the lower level of the Aruba Renaissance. That was unique.
Each of the Gaylord properties qualifies as interesting.
I really enjoyed the design of the Knoxville Marriott. I almost expected to see a monorail running through the 10-story lobby.
And I can't forget the Mauna Kea Beach Hotel on the Big Island.
The point is that there are so many hotels that are purely functional. We've all visited that type. I'm curious about the unique properties, specifically the hotels, not the locations. Even the JW Marriott in Grand Rapids is pretty cool (sorry no picture).
So, what's the most (architecturally) interesting Marriott you've visited?