Ironically, I think you're asking the wrong crowd about which accent is prefered. Despite many differing political views you have to admit that the English-speaking countries are amazingly aligned on a great deal of issues and so we have no animosity—and therefore no real preference—toward or among different accents. I think when you say "outside of the U.S.", what you're asking about is how others view you and, yes, those angry with U.S. foreign policy could possibly take offence and might actually prefer a different accent. Of course, if you're speaking to them in English, they might be at the point that most English speakers are at and not care about or associate accent with politics, in which case we go back to the original answer that it really doesn't matter.
Of course, all of this is assuming that you can even get rid of your own country's accent in the first place, which not a great percentage of speakers accomplish. As everybody's basically stated, people care more about being able to understand you than anything.
There's also the aspect of what's easier to learn when aligned with your native language. My wife is Chilean (I'm from the western U.S.) and she thinks British English is easier to speak than American English.
Probably the most important differences to consider are in vocab. (to native speakers). For example, I had a friend from England a number of years ago who was working on a project with me and asked me to pass him a rubber. He of course meant "eraser", but in AE it sounded like he was asking me to pass him a condom. I've also heard an English Teacher in Brazil (Michael Jacobs) teach "the phone's engaged" (BE) instead of "the phone's busy". In AE, the first example is never used. What you learn depends on who you interact with. Be aware of these differences.
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