Five American cities compared against national average
Well, that didn't take long:
1) Alexandria, VA has a higher than national average on robbery
2) Detroit, MI has a higher than national average on robbery, rape, murder, assault, burglary, and auto theft
3) Camden, NJ has a higher than national average on robbery, rape, murder,
assault, burglary, auto theft, and theft (which is every category)
4) Philadelphia, PA also has a higher than national average in all categories vs. the national average
5) ...but Oakland, near me, where we sometimes nickname it the crime capital of the us, actually has a theft rate lower than the national average, but still has higher rates of all other crime vs. the national average
so of the five medium to large to huge cities listed here that had at least one red flag on crime (but all considered major cities of over 50,000 people, actually in this case all cities over 75,000 people), Camden and Philadelphia are both more dangerous in all types of crime than the national average
and while some posters here on this thread have put in a good word for Detroit and Alexandria, neither city is safe as the numbers will tell from 2005 crime statistics (can't vouch for 2004 and before though

... (alexandria having a higher theft rate than detroit and higher robbery rate than the us average, and detroit having a higher rate of almost every type of crime than the us average)
but again, Alexandria and Detroit are safer than Camden and Philadelphia as compared against the national average in 2005 crime statistics
many cities did not compute a measureable amount on crime statistics because they were so low, but few were major metro areas in the US and in general, cities are more dangerous than the countryside