#1 Real Madrid

Yeah, this was not even a close fight.
Cristiano Ronaldo came close to breaking the internet with his inspired hat-trick against Spain in the opening game and then scored the winner against Morocco to lead the Golden Boot race momentarily. With Portugal facing Uruguay in the RO16, he will take on familiar foes in Diego Godin and Gimenez.
Luka Modric has been the best Croatian player across both the games, having scored in both and winning the man of the match award twice. Toni Kroos, despite having a shaky tournament so far, was responsible for Germany's 3 points against Sweden by scoring the goal of the tournament so far (once again, willing to fight anyone on this).
Isco, having scored his first goal of the WC against Morocco, is the driving force of the Spanish attack, and pops up into the opposition box at every possible juncture.
Casemiro and Marcelo haven't had the best of times at Brazil, but they are nothing close to being called shabby. As the tournament progresses further, we might be able to see them in much more pronounced roles.
Dani Carvajal and Sergio Ramos, along with their Barcelona counterparts form the rest of Spain's backline, while Nacho Monreal scored a beauty against Portugal to make amends for his mistake earlier in the game.
With Costa Rica, Keylor Navas was unlucky to be knocked out of the tournament despite putting in a strong performance across both the games. After their surprise run in the last tournament, they were unable to replicate the same form and lost both their games in the group.