Both I'd say. What's the fun in watching a league where the two teams are scoring goals for fun. You have no big derby or classic game to watch apart from Barca-Madrid.
Deportivo, Villareal, Atl. Madrid, Valencia all are a guaranteed 3points for either Barcelona or Madrid when they face them. What's the fun of it?
In England, you know your prediction is going to go either ways when Chelsea meet one of Arsenal, United, L'Pool etc.
Same case in Italy, we were just back from Serie B but didn't loose to Inter the champs in 2007 and won against other top teams. When Milan play one of Roma, Juve, Inter, Fiorentina, you know you can't predict let alone mid table teams.
In Spain it's not the case, you watch Barcelona to see them score 4 or 5, you watch Real Madrid to see them hammering the other side, can't no other team compete with these two?