Unfortunately, it's impossible to say "This car is the safest one around." A car that does well in the government's frontal impact crash test may not perform as well in an offset or side-impact test. It's best to look at different types of safety data and evaluate the car based on your own concerns. Here are some resources for your comparison:
The Highway Loss Data Institute publishes insurance claim data that rates most cars for injury, collision and theft, based on models from the previous three years. While perhaps not as scientific as a lab test, this kind of data may be a better indicator of real-world performance.
The Insurance Institute for Highway Safety has frontal-impact and frontal-offset crash test data on some new cars. The two tests complement each other; full-width frontal impact tests are especially demanding of restraints but less demanding of structure, while the reverse is true in offsets.
For more information, visit www.safercar.gov, which is a site produced by the National Highway Traffic Safety Administration and the US Department of Transportation.