The Clasico clashes have reached new levels in the last couple of years with both teams possessing outrageously talented squads.
The two Spanish giants are arguably the greatest teams in world soccer at the moment and selecting a combined XI will never be an easy task, but here's how the ultimate team might look.
The formation: 4-1-3-2
This is an easy one. There's a reason why Casillas is Spain's first-choice 'keeper with both Reina and Valdes inferior to him in the national team.
Agile, quick, intelligent and almost unbeatable, Casillas is arguably the best active goalkeeper in the world.
In November 2011, he became the most capped player of all time for the Spanish national team.
In the fight for the right-back spot, the Brazilian has just edged out Sergio Ramos.
In 2008, Alves joined Barcelona for 32.5 million euros, becoming the most expensive defender in history.
At Barcelona he plays as an attacking right-back, venturing forward at every given opportunity. Alves is tirelessly running up and down the right side, covering an impressive amount of ground.
He is rightly considered as one of the best fullbacks in the world.
A strong, robust defender well known for his impulsive character.
The Portuguese simply loves the physical side of the game. His great positioning and dominance in the aerial part of the game are his main strengths. But his hot-headed and temperamental character can sometimes get the better of his decision-making abilities.
Pepe is a great defender who is, unfortunately, slowly becoming a symbol of controversy.
The Catalan icon gets the nod ahead of his teammate Gerard Pique.
You can always expect Puyol to make his presence known to oncoming attackers. Strong in the air as well as in the tackle, the Blaugrana captain is also very tactically astute. He is also the backbone of one of the greatest sides in the history of soccer.
He won virtually every soccer tournament a player can win, including three UEFA Champions League and five La Liga titles.
Another easy pick.
The young Brazilian mainly plays as an attacking left-back, but can also play as a left winger.
Marcelo is not afraid to take on opponents and create chances for his teammates. His great passing and technical abilities always manage to impress.
The Brazilian has often been criticised for his poor defending, but has improved significantly lately.
It is often forgotten how important is the defensive midfielder.
Not only is he capable of providing defensive cover for his teammates, he can also provide the creative spark with his amazing ball-distribution ability. And his clever positioning always comes in handy. The Spaniard also has an intimidating long-range shot and is not afraid to challenge the keepers from distance.
Alonso is the key to imposing the style that suits the Real Madrid attacking stars.
Capable of breaking down the whole opposition defense with a simple through ball, the midfield maestro is a must-have in any team. His impeccable technique and eye for the pass make him arguably the finest midfielder in the modern game.
Already 32 years old, the Spaniard shows no signs of slowing down and continues to be the beating heart of the team.
This season his form has been inconsistent but he still deserves a spot in the team.
His constant running and vision on the pitch make him an important part of Madrid's attack.
His left foot is just magical. He can bend in corners, free kicks and crosses with this left foot with pinpoint accuracy.
His only downside is that he can only play as a playmaker. The German's defensive abilities are poor and he quickly becomes a liability when called upon to defend.
Yet another La Masia product in our team.
His great versatility, work ethic and creativity easily guarantee him a place in the team. Alongside Xavi, the Spaniard has set up standards for every modern midfielder. The Barcelona duo is famous for their perfectly weighted through balls and are probably the greatest passers in the game.
Despite being relatively young, Iniesta has won every possible title in soccer.
His 90 goals in 84 appearances for Los Blancos guarantee him a place in the team. Even more impressing is the fact he scored them playing mainly as a winger.
Regarded by many as the most complete modern soccer player, the Portuguese uses his left foot as much as the right one. His set pieces and crossing are admirable and his heading ability is just as good.
Our team wouldn't be complete without the most expensive soccer player in history.
There's always a place in any team for the three time Ballon d'Or winner. Even Diego Maradona, arguably the greatest soccer player in history, declared Messi as his "successor."
He can take on several defenders with ease and score goals for fun. The diminutive forward is every defender's nightmare.
Only 24, the Argentinian has already won three UEFA Champions League and two FIFA Club World Cup titles. If he continues to progress at the same rate, he might just overcome the likes of Pele and Maradona, and become the greatest player in history.