Whichever you want
I had a hard choice between them too, but when I was ordering they runned out of white models on the first 15 minutes of online store launch, so that maded me think that the white is more popular. So I just waited for 3 weeks to come (white one ) and no problems whatsoever.
Ps girls love white, so if ur a guy to show off then white is best
black one reminds kinda kindle or nexus, but the white just that shiny apple logo on the back makes it beautiful.
Good luck with your choice