The S-Class has not been crash-tested by the Insurance Institute for Highway Safety. Standard safety features include eight airbags, an electronic stability system and antilock brakes. Click here to see a full list.

Standard on the S550 and up is Mercedes' Attention Assist system, which monitors a number of factors to intuit driver drowsiness. It alerts you with warning chimes and instrument indicators. Other options include a night vision system with pedestrian detection and fully adaptive cruise control that can initiate automatic braking if a collision is imminent.

An optional lane departure warning system uses cameras to detect lane markings; at higher speeds it vibrates the steering wheel should you cross over without signaling. Our test car had it, and one editor found the system less effective for catching your attention than the audible chimes that go off in many competing systems.

Compare the 2009 and 2010 S-Class here. Mercedes products never come cheap, and the S-Class is a primary example. The 2010 S400 starts at $87,950, minus a $1,150 hybrid federal tax credit. That's around the same price as the long-wheelbase 7 Series but $9,300 more than the long-wheelbase Jaguar XJ — and more than $17,000 more than a long-wheelbase Lexus LS. (As of this writing, Audi's redesigned 2011 A8 hasn't been priced yet, but the 2010 A8 starts under $80,000.) Standard features on the S400 include an air suspension, the Harman Kardon stereo, heated 14-way power-adjustable front seats, xenon headlights, leather upholstery, a navigation system and a moonroof.

The S550 starts at $91,600. All-wheel drive effectively adds $4,000 — the system itself costs $3,000, but it dings gas mileage enough to incur a $1,000 federal gas-guzzler tax. Beyond that, pricing truly gets steep. The S63 AMG runs $133,550, the S600 $149,700 and the S65 a hefty $201,150. All three get a miserable 13 to 14 mpg combined — which bumps the guzzler tax up to $3,000. Options on lesser S-Class sedans include adaptive (swiveling) headlights, a backup camera, heated and ventilated seats for both rows, massaging front seats, power rear seats, a rear entertainment system with dual monitors, and a panoramic moonroof. Naturally, just about all of those features are standard on the S600 and S65.