Well firstly on the domestic competitions, a lot of people reckon that La Liga is the greatest league in the world and when you see games like last weekend most would agree. But IMO since Chelsea have become a powerhouse in English football the English game has become slightly better with all of the other major premiership sides trying to catch the blues which has made competition very good over the past two seasons.
But when you come down to strenght of the clubs & quality of players it evens out a bit i.e the top clubs in England are Chelsea, Man U, Arsenal, Liverpool, Tottenham & Newcastle (if they play to potential i guess) while in Spain its Barca, Real, Valencia, Ath.Madrid, Villareal. When it comes to crowd support and turn-outs both leagues are superb & fans equally fanatical about their clubs success which makes if even harder to understand why two countries with such great leagues that have some top players currently keep doing so badly on the international stage.
We all know about England, so i'll look at spain:
In defense on paper its as strong as any side in the world with Goal-keepers such Casillas (arguably the best shop stopper in the game), Reina, Valdez. Then in defense Puyol (one of the best defenders around), Pablo, Ramos (on of the best young full-backs currently), Marchena, Juanito, Salgado, Del Horno & Capedevilla.
Mid-field is very creative with the X-men, Jaoquin & Vicente (two of the best wingers in the buisness), Albelda, Garcia, Baraja along with good talented set of youngsters lead by the Fabregas & Silva.
Then going foward not many sides in world football can boast to have such firepower with the likes of Torres, Villa, Raul, Morientes, Angulo. But just like England they continue to flatter on the international stage.
For me come Euro 2008 an England vs Spain final would be great, but it will all depend on if Mclaren and Aragones can turn their side of talented players into world beaters.