Who is best, I don't know. I guess that would be a question that only Elvis himself could answer. None of them did anything wrong to me, and aside from Ginger who doesn't like to talk publicly I have heard wonderful bits of Elvis History I never knew about from all of them.
While they seemed to have good chemistry on screen and reportedly off as well, over the long haul I think both Elvis and Ann Margaret probably had too big
of egos to last. They were both used to being the center of attention at all times and eventually one of them wouldn't have been, and the one that wasn't
wouldn't like it.
I think they made a mistake by not teaming them back up for a second movie.