All of the hotels provide shuttles in one form or another. But, the hotels on Harbor Blvd. (Park Vue, Desert Inn, Carousel....) are the best as far as walking distance. You would still be walking quite a ways from the hotels on the other side of the parking structure to the trams.
I agree with PP. We stayed at the Super 8 on Ball Rd. and Disneyland Dr. that is "across the street from the Mickey & Friends parking lot" but it is a LOOOOONG walk. There is no sidewalk on the side of the parking lot so you have to walk on the opposite side of the street, past the parking structure, cross the street and back track to the tram......plus it's a huge hill.