final fantasy was always the big flagship of squaresoft and dragon quest of enix, and the biggest rivals. today both ip's belongs to square enix. but neverless we can say the battle between the two ip's was always interesting, at the most salewise...many would say dq is the winner in japan and ff worldwide...many things changed, both ip's improved in different directions..
but if we look in the future, for what game are you interested more, what ip of the next mainline entry has the better chances worldwide? still final fantasy, or will dragon quest take the crown?