GM is one of the biggest car manufacturers in the United States. Their overall brand encompasses more than one company, with names such as Chevrolet, Pontiac, and Buick (to name a few) all falling underneath the General Motors umbrella. And along the way, that company has been responsible for the success of some of America's most beloved sports cars and muscle cars.

But, despite making lots of good cars, they have also made some pretty bad ones too. We're talking complete lemons nobody wants anything to do with. Still, after seeing the 10 sickest GMs ever made, it will be hard to hate this company for the last 5 cars on the list, even if they were pretty disappointing.

15 Sick - Cadillac CTS-V

2019 CTS-V
via GM Authority

The Cadillac CTS-V was a very, very good run of cars. And the series met its end in 2019. It’s a shame it did as well. The CTS-V was a superb handling machine, one that really made you feel connected to it as a driver. The 640 horsepower coming from its 6.2L V8 made it a monster few American sports cars could compete with on the open road.

14 Sick - 1974 Chevrolet Camaro Z/28

via Barrett Jackson

You can’t really go wrong with a Chevrolet Camaro. Even in 2020. And the Camaro Z/28 was certainly one of the best of the range. Its brilliant styling was one reason it was such a big hit, especially when it had racing stripes over the hood. It helped raise Chevrolet’s profile at a time when their reputation was pretty low down.

RELATED: 10 GM Cars Every Collector Needs To Buy (And 10 They Should Avoid At All Costs)

13 Sick - Chevrolet Corvette ZR1

via Pak Wheels

There's the Corvette and then there's the Corvette ZR1 - one of the most powerful, aggressive, and downright thrilling sports cars America has ever seen. Pair this with the ever-improving quality and comfort of Corvettes in an effort to compete with European luxury supercars, and you have yourself one of the greatest sports cars on the US market today.

12 Sick - Pontiac GTO

via Wikipedia

The Pontiac GTO is a muscle car that many hold in as high a regard as the Ford Mustang. It's important to give a shoutout to this long-discontinued model, as it was a muscle car that once ruled the streets with its raw power. But aside from its performance, it also appealed to the masses for its insane styling, which made the Mustang look more like a Grand Tourer.

11 Sick - Buick Grand National GNX 1987

via Top Speed

The Buick Grand National of 1987 has sometimes been regarded as one of the best sports cars in the history of General Motors. It was also sadly a short-lived series, which many people lament. But, the pinnacle of the Grand National was definitely the GNX - a true sleeper with a turbocharger under the hood, boosting its power output to 276 horses. Dashing to 60 mph faster than cars with twice its power (in under 5 seconds), this was a truly exciting and surprising model.

10 Sick - 2002 Chevrolet Corvette

via Fast Lane Cars

The 2002 Chevrolet Corvette has to be one of the prettiest in the model's lineup. Look at the thing. Sleek, fast and modern, it properly brought the Corvette into the 21st century. Nowadays, they can be valued at nearly $20,000, and finding one in mint condition is something many desire to achieve.

RELATED: 10 GM Cars From The '90s That Make No Sense (And 12 From The '80s)

9 Sick - Chevrolet Monza

via Wikipedia

The Chevrolet Monza might be a controversial one here. As some people will say it never was what it was supposed to be, which is true. But many felt it was also discontinued early, as it was still a good machine that many have grown to really like over the years. A shame its production run wasn’t very long.

8 Sick - 2002 Pontiac Trans Am

via Classic Cars

The 2002 edition of the Pontiac Trans Am was the final car in the Trans Am range. At this time, Pontiac was going through a bit of a tough time so perhaps it’s not surprising they wanted to focus on newer cars. But the 2002 Trans Am was still mighty fast and had a great handling system, so to many, it was a sad day when the range concluded its run.

7 Sick - 1990 Chevrolet Corvette ZR1

via Barrett Jackson

There is something very cool about the way 1990 Chevrolet Corvette’s look. And the 1990 ZR1 is one gorgeous machine. It was a bold move to go for this look, and it paid off. It had awesome engine power and look every inch a sports car and drove like one too. This is now considered a classic.

6 Sick - 2008 Pontiac Grand Prix

via Car Gurus

2008 saw another Pontiac range close up. This time that of the Pontiac Grand Prix. And it was another sad day as well. Earlier editions of the car did have their issues but it evolved to be a great performer with equally good handling. It may never have looked the craziest, but it was one hell of a car to drive.

5 Fell Apart - Saturn Sky

via Motor Car Classics

The Saturn Sky was a car once hoped to save the brand. But it turned out to be anything but the Saturn savior. It was one of the worst cars that the company has ever made. Multiple engine and transmission issues plagued the Sky, which really hurt its reputation. Definitely glad it is not made anymore.

4 Fell Apart - Cadillac Allante

via Bring a Trailer

Where to even begin with the Allante? Well, let’s start with the looks. They were the epitome of boring. But that wasn’t it’s the biggest flaw. Cadillac put very little care into making the car and it suffered. Various issues plagued it and it was shoddily built, so GM will very much wish they had never built it.

RELATED: 25 GM Cars That Feel Right At Home At The Junkyard

3 Fell Apart - 1953 Chevrolet Corvette

via Classic Automobiles Inc

This is going to be a pretty controversial one, but hear us out. The original Corvette was not one of the company’s best cars. The car had multiple structural issues, which meant it had an incredibly short life span. Plus, its performance was terrible and not what the company had originally envisaged. It did look good though, it is a stunning machine.

2 Fell Apart - Chevrolet Cobalt SS

via Jalopnik

The Chevrolet Cobalt SS is one of the worst sports cars the US has seen. The whole purpose of the car is incredibly confusing, but in effect, it was meant to be something a bit more affordable. But like a lot of Chevrolet’s of the time, it suffered from corrosion and just a general lack of build quality.

1 Fell Apart - 1983 Pontiac Fiero

via Wikipedia

Whilst it is a pretty striking car, the 1983 Pontiac Fiero is not one that the company can be overly proud of. It had a horrible engine that caused all manner of issues, particularly with overheating. These issues plagued the poor Fiero which is a shame, as it was a brilliant looking machine.

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