I want to rent a apartment one day with my friends.
Here is the New Jersey police site where you can download pdf documents with all crime statistics.
I just clicked any and looked at the statistics for 2008. In there, the districts Hunterdon Cape May, Salem Sussex and Warren had the lowest number of crimes and the districts Camden and Essex had the highest. But they had absolute numbers in that file, not numbers of crimes per population. So I guess these differences might be due to the the different density of population. Of course larger towns/ districts with several large towns have more crimes absolute than uninhabited parts where you find one or two houses every other mile.
Monroe Township , I go there all the time. It's a really nice safe area :)