With each successive album from the late '70s to the late '80s, Prince further demonstrated his genius. He made bizarre, experimental, futuristic funk-pop that, despite being very weird musically and lyrically, was extremely popular. For the poll, I gave options of the three albums I believe represent him the best: the early and incestuous Dirty Mind, the mid-career magnum-opus Purple Rain, and the double-album masterpiece Sign O The Times. Understandably, your favorite was Purple Rain, a brilliant album and also one of the best pop albums ever. Sign O The Times came in second, and Dirty Mind placed third.
It's important to note that the reason I did this poll is because, lately, I've been listening almost exclusively to Sign O The Times, and it is rapidly finding its way into my shortlist for best albums ever. There's just something about it that makes it both my favorite Prince album and, now, one of my favorites of all time. I'll talk more about it when I revisit my Top Albums of the '80s list in a month or two.