I´m not following college ball, so my opinion on these kid´s games is based on very limited information.
Nevertheless, I think whoever picks Parker will regret it. Still has a lot of growing up to do, it seems he has been shielded from reality too much. He´ll face the same existential questions we´ve all faced at some point in our lives, only he will have money and fame in abundance. Don´t forget how perverted (not in a sexual sense) life under the spotlight can be, and life´s traps are manifold. Some take it better than others, and I have strong doubts regarding Parker. I think he´s a burn-out waiting to happen. Not to mention that his game might not translate to the NBA as well as one would hope.
Wiggins, on the other hand, seems to be way simpler constructed than Parker (which is a plus), and has been under the spotlight since he was a little boy. Considering that, I think it´s remarkable how team-oriented he plays, his effort on defense, and how he still tries to get his points in the flow of the game, rather than forcing the issue.
Granted, that´s a completely unscientific assessment of two of the most talked about rookies in this year´s draft, but I do believe that many people overlook the very real danger in taking Parker too high when they talk about the top of this draft.