By a country fucking mile.
I ain't even a Madonna fan, but she's a murderer when it comes to singles. She was consistently putting out killers right up until Hung Up or so (that's the last one I found interesting enough to listen to more than once, but that may be ABBA's fault--I think Madonna may have been running dry on singles since Music). I think Express Yourself is her best, but this is number 2 or 3. It's a fun pop song that makes you want to move. Also, the song is a fun cultural piece because it has fun controversy attached to it--makes the whole package, the song, video, controversy, a nice encapsulation of the fun bits of Madonna.
Not a big fan but I did almost buy a copy of her early 90s coffee table book Sex a few months back, but it's pricy and out of print and it appears to be a mess sorting out the differences between all the international versions. The Japanese version I think was cheapest (maybe even sub 100 bucks), but do they edit out/pixelate nudity in books that are meant for adults in Japan? I'm mentioning Sex because there's nude intimate photos of Madonna with fellow bad music nominee Vanilla Ice in it as they were dating at the time.
But I mainly want the book so I can be a small part of the classic SNL sketch that had Phil Hartman as Charlton Heston reading the book-on-tape version of it.