With 2010 model year vehicles already on dealer lots, Cars.com editors reminisced on the good, the bad and the ugly of the past decade to compile their top ten most-improved and worst cars of the decade.

"Despite the current gloom, automakers have really stepped up the past decade and have put out some great vehicles," says Patrick Olsen, editor in chief of Cars.com. "We've seen mass adoption of new vehicle types like crossovers and hybrids. On the other hand, we've also seen a lot of duds."

In order to be considered as one of the most-improved or worst cars of the decade, a car had to be sold at any point in the 2000s; some of these models were only on the market for a few years, while others are still being sold today.

Worst Cars of the 2000s:

Whether poorly executed, ill-conceived or downright dreadful to look at, the 10 cars listed below stood out to the Cars.com editors for all the wrong reasons.

10. Pontiac Aztek(2001-2005): The Aztek was criticized for the duration of its life for its ghastly styling. Were the critics wrong? Yeah, we didn't think so.

9. Daewoo Anything (1999-2002): We had just tested a Suzuki Esteem and marveled at how competent even the cheapest little econoboxes had become when a leather-lined Leganza midsize sedan showed up -- the best Daewoo had to offer. We mused over which would kill us first: the toxic gases from the cheap interior or the recalcitrant transmission and inconsistent acceleration. Three days into the loan, the first Daewoo crash tests in U.S. history came out, and we called Daewoo and told them to come pick up the car. We'd never done that before, and we haven't since.

8. Isuzu VehiCROSS(1999-2002): The outrageous Isuzu VehiCROSS two-door SUV, whose extreme styling drew varied reactions, lasted from 1999 to 2001, and even that's surprising. The fanglike grille uprights made it look like it would eat you, which was scary mainly because inside the VehiCROSS was a place no one wanted to be.

7. Jaguar X-Type(2002-2008): In the early 2000s, the class of entry-level luxury cars was growing. Wanting in, Jaguar came out with the X-Type. Sharing its front-drive platform with a European Ford Mondeo, the X-Type was a too-small, not-so-sporty sedan with all-wheel drive that was hamstrung by some of the forewarned quality issues.

6. Pontiac Sunfire(1995-2005): The Sunfire managed the rare feat of having a worse interior than its GM twin, the Chevy Cavalier. Cheap interior plastics run amok, a coarse four-cylinder engine and horrendous crash-test ratings sealed its fate.

5. Cadillac Catera(1997-2001): In the late '90s, the Opel Omega begat a Cadillac that was sporty in theory but soft and underpowered in practice, rear-wheel-drive in design but front-wheel-drive in feel. And that's just the car. Cadillac didn't help its case with advertising that included the tagline "The Caddy That Zigs," supermodel Cindy Crawford, an animated duck, and the suggestion to "lease a Catera" with the response, "Who's Lisa Catera?" The geniuses responsible for the Catera should have been exiled, but we suspect they went on to develop something called the Pontiac Aztek.

4. Toyota Echo(2000-2005): The Echo subcompact's high seating position and center-mounted instrument panel were two well-intentioned features that were summarily rejected by consumers (though they would find their proponents in later years and other models). Call the Echo ahead of its time if you must; mainly it just wasn't a very good car.

3. Jeep Compass(2007-present): The Compass doesn't belong in the Jeep lineup, a brand known and respected for its off-road ability. It's a soft-roading poseur, and not a good one at that.

2. Chrysler Sebring(1995-present): The previous-generation Sebring wasn't a bad car in its day, but Chrysler dropped the ball with the redesigned 2007 model. With a weak base powertrain, uncomfortable front seats, poor interior quality and haphazard styling, it never had a chance in the highly competitive midsize-sedan segment.

1. Smart ForTwo(2008-present): We don't have a problem with small cars in general (we're big fans of the Mini Cooper), just with ones that don't deliver on the benefits of going small. The pint-sized ForTwo sacrifices a lot of passenger space for a relatively unimpressive 41 mpg on the highway, has an SUV-like propensity to roll over, and is equipped with an aggravating sequential manual transmission. Sure, the ForTwo looks cute, but after you drive it you won't be smiling anymore.

Most-Improved Cars of the 2000s:

Most-improved awards are a mixed blessing: part insult, part praise. Such is the case with Cars.com editor's top 10.

10. Saturn Vue: The Saturn Vue was in a relatively good position when it launched in 2002. Unfortunately, the Vue was underwhelming. The 2008 Vue redesign garnered a reaction more often attributed to the all-new Chevy Malibu: "This is a GM interior?!" The classed-up Vue is worlds better than the original.

9. Cadillac Escalade: 10 years ago Lincoln was dominating pop culture with a concept any reasonable auto exec would have thought ridiculous: a full-size luxury SUV. GM saw the popularity and promptly slapped some Cadillac badges and leather on a Chevrolet Tahoe and called it the 1999 Escalade. Not enough lipstick, too much pig. But Cadillac went all-out for the 2001 model, which leapfrogged the Navigator in terms of power and interior quality, and before long it was the Caddy that you saw in the hands of hip-hop artists, real and imagined. For posterity, drive a late-model Escalade or Escalade Hybrid before they're extinct. You'll be impressed.

8. Mercedes-Benz C-Class: The painfully plain 2000 C-Class counted among its engines a supercharged 2.3-liter four-cylinder that had all the refinement of a burr grinder. Its aesthetics were as appealing as a larger Mercedes, which is to say ... yawn. Thankfully, a 2001 redesign updated the C's exterior styling, though it still looked like an S-Class that had shrunk in the wash. For 2008, Mercedes got the message, and the C-Class leaves the decade with edgier styling, more interior space and even some sporty reflexes to lure buyers away from Audi and BMW.

7. Cadillac CTS: When the Cadillac CTS hit the market in 2003, American auto writers went overboard with praise. The car's handling was the closest any domestic car had come to competing with European luxury sedans, which was promising, but the exterior styling looked like it had been yanked off the drawing board unfinished. The CTS makes the list because of the brilliant 2008-09 model, perhaps the most world-class vehicle ever to come out of Detroit. The styling, performance and interior quality are stunning and quintessentially American.

6. Kia Sportage: Kia resurrected the Sportage name in 2005 after a two-year hiatus, so perhaps this is a technicality. We're citing the Sportage compact SUV because it represents a couple of important milestones: the move from truck-based to car-based SUVs, and Kia's transformation from a punch line to a formidable market competitor. Though a decent-looking little SUV, the 2000-02 Sportage was based on a rear-wheel-drive truck platform with old-fashioned recirculating-ball steering, an unrefined drivetrain, a noisy interior and -- at best -- 19 mpg. The 2005-09 Sportage is a roomier, more refined car-based model that gets 22 mpg despite its added features and improved crashworthiness. The Sportage has come a long way.

5. Nissan Altima: A little-known fact: The Nissan Altima is the third-best-selling midsize sedan in the U.S., nipping at the Honda Accord's and Toyota Camry's heels. Its accomplishment since 2002 is how it's provided sportier looks and driving than the big dogs have, without sacrificing livability.

4. Hyundai Sonata: The 1999-2005 Sonata wasn't exactly exceptional. It was a step up from the previous generation, yes, but it had a lingering low-budget finish and was a step behind the class leaders in crash tests. The 2006 redesign was a sucker-punch to the competition -- a bargain-priced entry loaded with standard features, including six airbags and stability control. It had sharp styling and competitive interior quality, both of which improved in 2009, along with power and efficiency.

3. Toyota Prius: The 2004-09 Toyota Prius is a marvel -- not simply because it's so efficient, affordable and reliable, nor because it has single handedly brought about global acceptance of new and scary technology. No, it's a marvel because even when it yielded its position to the next-generation 2010 Prius, it still reigned as the most efficient and affordable hybrid on the market. The original Prius that was sold in the U.S. -- from 2001 to 2003 -- was a technological triumph for its time, but it was nothing like the phenomenon that soon took its place.

2. Ford Mustang: The Mustang's redesign for 2005 made it a very good car -- and, at the time, the only remaining model in the muscle-car class. It's on this list, though, because its predecessor was beat. The 2004 model year was the car's 25th year on a platform Ford had long since abandoned for other purposes. Those 'Stangs shuddered out of dealerships as if bolts and welds were missing. The seating position and interior quality were equally unrefined. Come 2005, the new Mustang's retro styling was the highlight of auto shows and the driver of many, many sales, but the new chassis is what really kept this model in the game.

1. Chevrolet Malibu: The Malibu has been a critical and sales success since its redesign for 2008, especially in terms of its interior quality and refinement. It's not only competitive with leading midsize sedans, it surpasses a few in some respects, including mileage. Its spot atop our most-improved list, though, has more to do with its poor showing in its prior two generations. It was a rental-car staple through 2003, followed by an overly hyped redesign in 2004 whose peculiar styling, vague steering and interior quality didn't deliver.