This is a tough one for me as I know both players and I know my two eldest sons often have debates about this as my eldest is a Manchester United fan and Cristiano Ronaldo used to play for them so he is a huge fan of Ronaldo but my other eldest son, he is not a fan of Manchester United and therefore his favourite is Messi.
My youngest son is not too bothered.
From what I know of both players, I myself would have to go for Messi as I feel he is a little less self-centred and full of himself compared to Ronaldo.