Well, I guess they are all fun. I hadn't seen this one before - it features miniature hats. (1950s - Indianapolis Museum of Art)
Always loved that one! Among collectors it is one of the most sought after. Each one was different and he only made a few.
I went to the Chicago History Museum's Mainbocher exhibit in 2016, and they had a single case of Bes-Ben hats, which I photographed. Nothing quite as amazing as your Hat hat, but I also loved this description of his annual clearance sale, which was held in Chicago, on Michigan Avenue. Catch it and you keep it!
That sale description is WILD. Of course I think of the bride tossing her bouquet and people getting trampled.