Say the word "hybrid" and then ask drivers, anywhere in the world, to name a car brand.

They'll likely say "Toyota," a testimony to that brand's launch of the first Prius in 1997 and its tenacious pursuit of improvement in hybrid-electric powertrain technology since then.

Today, Toyota announced it has delivered 5 million hybrids worldwide--and almost 2 million of them were sold in the United States.

To mark the occasion, the company issued not only a press release filled with the obligatory statements from executives and external analysts, but a truly unusual video.

In it, happy young hybrid owners sing, dance, and otherwise cavort around the complete model lineup of 2013 Toyota Prius hybrids: the traditional Prius liftback, the Prius V wagon, the Prius C subcompact hatchback, and the Prius Plug-in Hybrid.

We'll let you decide how to assess the video.

About all we can say is that ... well ... it's probably better than the infamous Volt Dance.

The Toyota Prius is now midway through its third generation, launched early in 2009 as a 2010 model.

Three of the four Prius models are rated at 50 mpg combined by the EPA, with the fourth--the bigger, heavier Prius V wagon--rated at 42 mpg combined.

That makes those Prius models the most fuel-efficient gasoline cars sold in the States; no other car gets higher gas mileage.

The basic technology has remained the same for more than a decade: a small four-cylinder gasoline engine is paired with a Hybrid Synergy Drive transmission containing two electric motor-generators.

The motors can power the car, alone under light loads or assisting the gasoline engine when maximum power is needed. They also recharge the car's nickel-metal hydride battery pack, either on engine overrun or through regenerative braking.

From that first Prius, Toyota has slowly spread its hybrid technology throughout its lineup, pledging that before the end of the decade, it will offer a hybrid variation of every high-volume car it sells.

The Toyota Prius remains by far the best-selling hybrid globally, and the most efficient vehicle in Toyota's entire lineup.

A new fourth-generation Prius is likely to arrive in 2015 for the 2016 model year.

Leave us your thoughts--on hybrids, on Toyota, and on the video--in the Comments below.

+++++++++++

Follow GreenCarReports on Facebook and Twitter.