4. Giorgio Chiellini & Andrea Barzagli (Italy and Juventus)
Similar to #5, this partnership could be formed with another player from the club - in this case, it's a toss-up between Barzagli and Bonucci. As Juventus use a threesome at the back, formed of the aforementioned two and vice-captain Giorgio Chiellini, along with the fact that both Bonucci and Barzagli are world-class centre backs, it's hard to distinguish between the two. I've opted for Barzagli as he, quite simply, has won a World Cup with Italy, has more caps for his country and is more known for being an old fashioned defender. Bonucci is a ball-playing defender insofar as he can play long, accurate passes and is perhaps best known for starting attacks from the back. Of course, aerial ability and man marking are strengths for Leonardo, but I digress. Barzagli, on the other hand, is more known for characteristics mostly associated with defenders - positioning and strength, whilst also showing that he is gifted with the ball at his feet. Juventus are known for producing world class defenders, but have also been known for signing flops (see Jean-Alain Boumsong). Barzagli cost the club just over £200k at a time when he had not been capped by his country for three years. Now, at 32, he's a regular for Italy and one of the finest defenders in the Serie A. Good bit of business, that. Chiellini possesses the attributes that are crucial to Juventus' recent success and similarly mostly to the 'old-fashioned' centre back. Albeit Giorgio may be lacking in terms of on-the-ball skills, he more than makes up for this with his awareness, intelligence and immense tackling. Barzagli and Chiellini form a tremendous partnership and in conjunction with fellow-Italian Bonucci, form an almost-unstoppable force.