They are incomparable and Luis Ronaldo is more bright person in the world football. I think that such situation is curious because of time when these both players did their achievements.
There has been alot of talk about Cristiano being one of the greatest player of all time if Cristiano wins the Euros 2008 winners medal. Ok, now I agree that Cristiano Ronaldo is one of the best players in the world right now (though not the best) but we should not all get carried away that quickly and forget legendary names who have performed on the biggest of stages and done everything there is to be done. Names like Ronaldinho, Zidane, Figo and especially RONALDO who are all of the same generation of players as Cristiano Ronaldo or one generation before.
The name "Ronaldo" is indeed for football players... Well,I vote Ronaldo Brazil over C. Ronaldo if we are dealing with how they play in the field... For other aspect, you better decide...
What a funny question. Depends on when, Ronaldo during the 2000 was a good player. Now he has retired. I'll vote for Ronaldo Brasil when he was young and fast, not when he was overweight and slow.