Here, let me tell you why I own two GM cars and a Jaguar XJS.
My first car was a 1995 Buick Regal Custom. I've turned it into a track day car, supercharged 3800 swap and all. Why do I love it? Because its extremely easy to work on. The first engine lasted 217,000 miles (bought at 61k), right up until I accidentally overheated it, and the heat evidently damaged one of the lifters, causing it to basically grenade on me a few hundred miles later. Up until that point, it was extremely reliable, and driven very hard. Its now getting a supercharged 3800 engine put in.
When I say extremely easy to work on, I mean I can change the water pump in 30 minutes with my eyes closed, and the alternator in 15 minutes with my eyes closed. I can change the lower intake manifold gaskets in 3 hours from start to finish, and everything is cheap. $25 water pump cheap. The transmissions are reliable in my opinion, so long as they're maintained. Its ignorance that causes a lot of these cars to be unreliable; people who think they can go 150,000 miles on the original transmission fluid.
I bought my Bonneville GXP because I needed a bigger car. One has a hard time finding a better looking car on the road as a 4 door sports sedan. It has a bulletproof drivetrain, is very comfortable, and has served me well. There have been problems here, but all have been worth the car.
Why do I own a Jaguar XJS? Because I like the sound of a V12, and because its bolted to a GM Turbo 400 transmission, arguably the most reliable american transmission ever made. The electronics are American, the rear differential is made by the Dana corporation, also American, as are many suspension and steering components.
Looking back, having put 150k+ miles on my first car, a 1995 Buick Regal, I can honestly say I would do it again in a heartbeat.
Overall, these cars have very low maintenance costs, many have a fairly large aftermarket, they're easy to work on, and contrary to what the media will tell you, they're fairly reliable and get great gas mileage.
Consider that my 3.8L V6 in a 3200lb car got 30.5mpg average @ 70mph highway on a 700 mile round trip from Chicago to northern Wisconsin. Consider that my cousin'* Supercharged 3.8L V6 in a 3550lb car got 31mpg average @ 75mph on a 1500 mile round trip from So. Cali to Idaho. Consider that all the imports rate their fuel economy at 55mph, and you'll find that a GM is actually one heck of a car.
Want to buy a truck? You have nowhere to go but American cars. Remember that Chevy commercial in the 90'* "like a rock?"
"Chevy: the most dependable, longest lasting trucks on the road." And wouldn't you know it, the Wisconsin guy who ran his 1991 Silverado with the same engine for over 1 million miles proved that last year.