I think the question for this topic was phrased wrong.
You should change it to:
English English VS. American English
It would help you understand the answer better ![Wink [;)]](/emoticons/emotion-5.gif)
"american english" is such a peculiar phrase, a complete paradox in so many ways.
In any case there is not much difference between the two, Americanised English tends to have a strong basis of colloqial slurs - based on the strong accents of the first settlers. It tends to be more "rounder" "lazy" and "fluid"
I personally adore the accent found on most american male filmstars of the 1950's - So dignified.
Aside from that I find american accents quite irratating.
It doesnt sound very elegant/sophisticated and lacks clarity/definition.
We have so many strong regional accents in England, is is amazing how none of them filter down to the "standard" English.
Standard English is a very "clean" with a unnaccented sound, it is definetely the best for a learner and will help them to differentiate pronunciation of words more effectiveley.
It is also more respected by employers.