I say Argentina. Messi has been saving himself in the latter stages of the season, running 5km per match where he'd normally run double that.
Spain is a little passed their peak. Brazil might succumb to the pressure and Neymar had a pretty bad season.
I hope for a surprise from Belgium, very talented group, especially that young guy from ManU, Januzay, and of course the guy from Chelsea, Hazard.
Chile could surprise as well, fluent attacking style, but has Vidal recovered?
France and Columbia are hampered without Ribery and Falcao, a real pity