While I like sleepers as much as anyone else, I've always thought the MK3 looked best with a wing, whether it's the 87-88 one piece wing, the 89+ three piece wing or an aftermarket whaletail. But please, for the love of Supras everywhere, don't put on a huge "ricer" wing...
Ultimately, though, it's your car, so it's your decision as to whether you decide to keep a wing on it or not. I'm sure you already know this, but if you DO decide to remove the wing, you'll have to fill in the factory mounting holes. Obviously, that means using Bondo, which could crack and pop out over time, especially if the Bondo isn't applied right. It's just a thought...
Joe