He's more versatile
Ronaldo can play the role of winger, attacking midfielder or striker and always manages to be the most important player in the team, whether that's at Manchester United, Madrid or for Portugal. Can Messi play on the wing? Probably, but not with the same impact as CR7.
Better in the air
Quite simply, Ronaldo is more of a threat in the air than Messi. The Portuguese is an aerial menace, while Messi's headed goals remain collector's items.
Lionel Messi can dribble past entire defences using only his left foot, but what about his right? His right is significantly weaker, while Ronaldo is genuinely two-footed and is as much a danger with his left as his right.
Better for his country
Cristiano Ronaldo has produced in World Cups and major tournaments for his country, and continues to be the main man for Portugal. Traditionally, Messi does not perform at anywhere near his peak for Argentina.
Has proved himself outside of Spain
While Messi has only illustrated his magnificent ability in Spain, Ronaldo has also done it in the Premier League, the toughest, most physically demanding league of them all. Take Messi out of La Liga, and how good would he be?
Who do you think is better? Check our brilliant new Ronaldo vs Messi infographic
Ronaldo's Madrid visit Barca this weekend - check the latest odds.