I felt like Buenos Aires was extremely safe. I walked around at night without any problems. I was surprised at how safe it was for the economy being as bad as it was. Just saw this and floored to see BA higher than most cities in the USA too.
Buenos Aires has always been very safe. There is pick pocketing like most major cities but I have always found it safe at least in the nicer neighborhoods. @Jakoval has posted about crime in Conurbano which sounds rough.