One thing that I really wish Detroit had was a CityPass. I truly believe a CityPass would increase tourism in our area. It would show the people outside the area who say there is nothing to do in Detroit what we have to offer.

Just off the top of my head, I'd include:
Detroit Zoo
The Henry Ford
DIA
Detroit/Michigan Science Center
Motown Museum
Wright African American Museum
Belle Isle Aquarium [[if they ever get that open full-time)
etc.