If you've liked what you've seen of Michael Douglas, Basic Instinct is the movie you need to see of his.
Wall Street may be his "best" movie, or biggest, what have you, maybe even Fatal Attraction, but Basic Instinct was by far his best work IMO. (not him personally, best film I mean)
And of course, it's what made Sharon Stone famous, and for good reason I might add.
That film is so damn underrated, because it was so overrated early. If that movie came out now, it would be received much better. (Well, unless it was today's Douglas and Stone of course, that wouldn't be good.