I think Jyqmbo has lost it.
My personal favorite... hmm, it's hard to choose as I love the entire album. I'd have to say "Gypsy" though.
What do I love about it? Gosh... what's not to love? Stevie's voice sounds utterly majestic, and it absolutely soars in several places. The lyrics are wistful and evocative. The harmonies are lush. The music rises and falls with great purposefullness. And it has one of the single best codas of any Mac song, in my humble opinion.
So there you have it.