I prefer American English because it sounds more natural and beautiful than British English.
And, in my opinion, it is easier for a French speaking person to get an American Accent than a British one.
But the fact is that in almost all over the world people are learning British English.
So many people are more intersting to get a British Accent.
P.S: My accent is a mixture of American and British English. (LOL)
But I wanna get both of them.