Verbatim runs their own plants, so the country doesn't matter much. (It does with most brands).
If I recall, though, Verb quality vs. country, has been debated by people who burn ridiculous numbers of dvds.
And, of course, there's always variability by batch. (Which is hard to accept when you're paying for dual-layer).
I like Rima.com, for ordering. But then they're almost local, to me, so ground gets here in a couple of days. (Meaning I haven't tried others). They've got a good rep, too.
Taiwanese manufacturers make 'em cheap. They haven't developed long-lasting dyes.
There's at least one manufacturer that licences a Taiwanese manufacturer to use a good dye, but I don't recall the name anymore (one of the good-rep ones), so the problem doesn't apply to that brand.