Interesting question. My first choice would be Yugo, but since that's not allowed, I'd say that I'd buy from all car companies. If Kia were to come out with a great car tomorrow, I certaintly wouldn't pass it up just because it's a Kia. I mean, right now, I would never buy a Pontiac, but once the GTO or (fingers crossed) Solstice are available, I'd buy either one of them. I'm driving a 95 Olds right now, and it's been fine so far. My dad put over 100k on an 86 Olds, and rust was the major problem, not the engine or anything like that. If I had to choose, I guess I'd say Ford, as I find all their models to be ugly, or in the case of the Focus, a decent car but horribly prone to breakdowns. But even with Ford, I'd snap up the GT 40 in a second if I had the cash.
Edit: Forgot about Buick. There's my answer. I wouldn't be caught dead in anything Buick has to offer, and they have nothing interesting in the pipeline that I've seen. So, Buick it is. Disregard the above.