There are probably seven or eight nice neighborhoods in Detroit. If I was to pick two it would be Indian Village or Palmer Park which both have their own private security 24 hours a day. Big well kept houses with narrow streets.
A few more better than average would be downtown, Corktown, N. Rosedale, S. Rosedale (where I grew up)and Sherwood Forest. I tell people to think of Detroit not as a big monolith but as a series of villages, some are OK to visit and others are to be avoided at all costs.