As an Anglophile and a firm believer that "The Sun Never Sets On the British Empire" I'll have to agree with the British side of the argument. For American English to be the "most original" form of English is just rubbish. Sure, the words have changed over 400+ years, but there's been a LOT more influence on American English from the multitudes of immigrants from countries all over the world in the US over the last 100 years than there ever was in the UK, even though England ruled quite a lot of the world up until the 1950's.
Out of personal preference, I prefer the British form of English, since that's the origin of the language to begin with. An intelligent American individual has absolutely no difficulty understanding a person from the UK or Australia or even India if they pay attention to the subtle differences in certain words. At least, I have no difficulty because I take the time to educate myself, hence the "Anglophilia". (God, that sounds like a sexual deviancy!)
Eric, Well said!!! You refer to an intelligent American can understand a person speaking 'British' English. I have found in my experience something quite different. When in Miami last year, I asked for a beef sandwich. The girl behind the counter didn't understand and she asked me to repeat. She said "oh you mean a ROAST beef sandwich?". I missed ROAST out and would would have thought I was speaking Japanese! This is only simple example. I have many, many more!