depends on your needs. personally i'd go for the Jap if i need a long term well perform and less headache. I'd go for the german if i want to show off :p and i'd go for american if i want a strong fast monster :p
Japanese. My first car was a Chevy, and I loved it. But every vehicle I have owned since then (except for my work trucks) has been either a Mazda or a Nissan. And, except for an old Sentra that gave me some trouble, I've never had any serious problem with any vehicle. That's not to say that Mazda & Nissan are superior to Chevy or Ford or BMW or Mercedes. I have nothing against American makes or European vehicles. But I've always owned Japanese and I suppose I always will. It works for me.- the 5 different work trucks I've owned over the years have all been Ford F-250s. Again, just personal preference.
As a non-american I can honestly say would never buy an american car as the quality isn't their, germans make excellent cars but it I don't like the VW's as they are really getting to cheap to buy (which in my book means inferior quality) and the BMW's are becoming a dime a dozen as has definitely lost their prestige due to to many models being released. The Japanese cars are generally top quality, reliable and keep thier value better than the others and are competitively priced so a brand like Honda has always had an excellent name, but I would not even think at looking at a Subaru again seems to be a dime a dozen rule. Final answer would be a Japanese car would be my preference, unless you offered me a Jaguar.
If you are looking for drift go for Japanese cars. If you are looking for V12 and high top speed, go for European cars. If you are looking for drag cars or high-power cars go for American cars. These cars are known as: Tuner-Japeneese Muscle-American Exotic-European