As of easiness American dialect is easier to understand and talk. Also we can't say British dialect is hard because it is not, a little bit of practice and you won't miss a word they say. American dialect is by far the most used dialect around the world and on broadcasting agencies. But in most of the recent American movies, series they have screwed the English it might sound funnier yes but not respectful, also I talk both accents and I prefer American one, but I admire British accent more, and I use British accent at University, Work, in formal departments and so. For American accent speaking movies you might want to watch the God Father Trilogy, Cop Out, and maybe some social one like Our Idiot Brother, or some comedy like Burn after reading, Pulp Fiction, etc. For British accent movies like The Scarlet Pimpernel, Ladies In Lavender, About a Boy, Foyle’s War: The German Woman, etc. Hope this helps.

If you're asking which accent is easier to understand, then I would say American accent. But I love British accent more, because it has the natural, smooth and discreet European sound.

Personally,I like American accent,coz it seems more comfortable.And ,I will recommand you the TV Series named "The desperate housewife", because you can enjoy the authentic american accent there.wishing you a happy learning time.