Modesto's a pretty big city, so like anywhere else there are good and bad parts. So it all depends on where you live. This was the Modesto metro area, which includes the whole county.
Ceres ain't bad at all. There are a few bad areas, like El Campo and 10th St, but I would walk through almost any part of Ceres at any time of the day.
The bad parts of Stanislaus County are South Modesto, East Modesto (Airport), West Modesto, Highway Village (In Modesto), Southside Turlock, and a few smaller neighborhoods throughout the other cities.
I would say that overall Stockton is worse as far as crime goes. In Modesto, the southern 1/2 of the city is all bad, and above that it is mostly good with a few bad neighborhoods sprinkled throughout. In Stockton it is just the Far-North side that is good and even there there are some bad areas. But this ranking is based on crime, economy, unemployment, air quality, etc. It's considered the worst place to live.
Even though those other places like Detroit might have higher crime rates n other shit, there is a lot more they are considering than just that.
Hex4dub, which part of Modesto did you live in?