You don't have to spend big bucks to get a great, safe car -- but if you do, the 2015 Mercedes-Benz E-Class sedan is a strong choice. Source: Mercedes-Benz

What are the safest cars you can buy?

To some extent, that depends on how you define "safest." Lots of factors contribute to making a car "safe," whether it's great brakes and nimble handling that help you avoid accidents, or a crashworthy structure that helps protect passengers when the worst happens.

Braking and handling comparisons don't tell us a whole lot -- the winners are nearly always sports cars, but most modern vehicles do just fine. But the independent crash testing done by the Insurance Institute for Highway Safety, or IIHS, can tell us a lot about how well a car will protect its passengers when a crash can't be avoided.

The models that do the very best in IIHS's crash tests and do well at crash prevention are given the rating "Top Safety Pick Plus," or "TSP+." Here are some of the models that earned that rating for 2015 -- and that are "Recommended" overall by Consumer Reports. 

One note: IIHS says that most of these choices only qualify for their top-most rating when equipped with optional front crash-prevention technology, so take that into consideration when you visit your dealership.

Safest small cars
Among smaller vehicles, the Mazda3 sedan, Subaru's small Impreza and its SUV-ish sibling, the XV Crosstrek, and Toyota's (TM -2.21%) ubiquitous Prius hybrid made the cut.

The 2015 Mazda3 combines sporty handling, strong fuel-economy ratings, and a top rating for safety. Source: Mazda.

Mazda's compact combines great handling and a fun, sporty character with strong fuel economy, while the Subaru siblings deliver on the brand's dependable, go-anywhere promise. And the Prius, of course, is merely the world's best-selling hybrid car.

Safest midsize cars
One size up, but the winners' names are the same. Subaru's Legacy and Outback twins, the midsize Mazda6 and Toyota Camry sedans, and Toyota's bigger Prius V hybrid take home the prizes.  

The strong-selling 2015 Subaru Outback is well-regarded for both safety and dependability. Source: Subaru.

These weren't the only midsize cars to win IIHS's top nod, though. We should note that Fiat Chrysler's (FCAU) increasingly popular Chrysler 200 sedan also won the TSP+ designation for safety. But it didn't quite make the cut to be recommended by Consumer Reports, which was unimpressed by the 200's ride and handling.

Safest luxury sedans
Volkswagen's (VWAGY -1.90%) Audi division and Daimler's (MBGA.F -1.52%) Mercedes-Benz are fierce rivals in the lucrative and growing global market for luxury cars. Both brands consider safety to be a strong selling point, and their midsize sedan stalwarts -- Audi's A6 and Mercedes' E-Class -- both managed top honors here, as did the quick and sporty Infiniti Q70 from Nissan's (NSANY -0.13%) rising luxury-car brand.

(A couple of notes before you go shopping: The IIHS says that its top rating for the Audi A6 applies only to vehicles built after January 2015, and its rating for the Infiniti Q70 does not apply to V8-powered 4-wheel-drive versions.) 

Consumer Reports liked the 2015 Infiniti Q70 sedan, and it also performed very well in the IIHS's crash testing. Source: Nissan.

But where's BMW (BAMXF 1.97%)? BMW's 5 Series won the "Recommended" designation from Consumer Reports -- but while it did well in most of the IIHS's tests, it fell a bit short in the Institute's "small overlap front" crash test.

Safest SUVs
It may seem strange that we haven't seen Honda's (HMC -1.98%) name on this list yet. Hondas generally do quite well in both crash testing and Consumer Reports' evaluations, but only one Honda managed to win the TSP+ rating this year: The super-popular CR-V crossover SUV.

The Honda CR-V is a strong choice in the hot-selling compact SUV segment. Source: Honda.

Two of the CR-Vs compact rivals, the Mazda CX-5 and Subaru Forester, also made the grade for 2015. Honda's Acura MDX also made the cut among larger SUVs, as did Toyota's Highlander and Volvo's XC60.

As you'd expect from a safety-minded brand, several Volvos earned the TSP+ designation -- but Consumer Reports failed to recommend them for other reasons.

Safest minivans
Want a safe, well-rated minivan? Look no further than the Toyota Sienna, the only minivan to make the cut -- although Honda's Odyssey did very well in the IIHS's crash tests and just missed the top-most rating. 

To be fair, either van would be a fine choice. Consumer Reports praises the Odyssey's "responsive handling and supple ride" and rates it a little higher than the "sensible" Sienna, which loses a few points for "lackluster" handling but wins praise for reliability.