An undiscovered gem when he moved from the Russian league to Manchester United, Nemanja Vidic has ably partnered Rio Ferdinand in central defense at Old Trafford to the tune of a Champions League title and three straight Premier League crowns. Equally impressive with a resolute Serbian back four, Vidic possesses grit and grace all in one tough package, but is also more than capable of contributing set piece goals on the offensive end when necessary.
Giorgio Chiellini, Italy
The Italians have always been able to play their style with great success thanks in major part to their strong defense, and no other Italian back is currently doing the job better than Giorigio Chiellini. While Juventus has struggled mightily this season in Serie A, Chiellini has been admirable for the most part, but it's while wearing the Azzurri shirt that he seems to put on his best displays. He is a lockdown, old-fashioned defender who stays home and makes sure that Italy's typical 1-0 lead holds up over 90 minutes.
Philipp Lahm, Germany
Philipp Lahm of Germany may not be the biggest defender in the world, but what he lacks in size he more than makes up for with great timing, positioning and anticipation. His great pace also keeps opposing players wary of the threat he poses going forward as his marauding runs are often the start of yet another German goal-scoring opportunity. Lahm is also not afraid to shoot from distance when in the attacking third, and does so with great accuracy.
John Terry, England
The former England skipper will have a lot on his mind in South Africa following allegations about an in-team affair that threatens to harm the Three Lions' World Cup hopes. But the steady Chelsea defender continues to go about his business in strong fashion. Terry is a rock at the back for the Blues and has a reputation for bringing down opposing forwards with great ferocity, but he is also quite adept at heading in goals for his team off corners and set pieces.
Sergio Ramos, Spain
When you play on the world's most expensive squad, being one of the few penciled-in starters week in and week out is quite a feat, but it's nothing new for Real Madrid right back Sergio Ramos. The Spanish star is well known for his tough tackling, but he can also contribute the odd goal here and there to help his team to victory.
After what seems like an endless career, it's hard to believe that Lucio is only 31 years old after a career that started back in Brazil, then moved on to Germany (with two clubs), and now has shifted to Italy, where he plays with Inter Milan. Lucio is often the central defender providing the game-saving clearance or block when needed most, but he is also dangerous off set pieces and corner kicks with his heading ability. More patient and composed than he was in years past, Lucio is a prime example of a defender simply getting better with age.
Gerard Pique, Spain
While Carles Puyol provides the experience in the Spanish back four, Gerard Pique is the young stallion who has impressed fans and pundits around the world over the last few seasons. Alongside Puyol at the Nou Camp, Pique has claimed every significant trophy in Europe, and with Spain, he collected the Euro 2008 trophy as well. His time with Manchester United served him well, but Pique has blossomed into one of the world's best in Barcelona.
Patrice Evra, France
It took Patrice Evra a season or two to find his feet with Manchester United, but once he did, the Frenchman was a crucial factor in the Red Devils' success over the past four seasons. With France, Evra provides veteran leadership and rock-solid defense, while his pace and vision always see him getting into dangerous positions in attack.
Dani Alves, Brazil
In the great tradition of Brazilian defenders like Roberto Carlos, Dani Alves combines athleticism and skill to the right back position, and an uncanny ability to score with deadly free kicks. With Barcelona, Alves has already won every club title there is to win, but there will be no complacency as the talented defender aims to help carry Brazil to a sixth World Cup title. Alves is a capable defender but certainly brings more to the table with his overlapping runs into midfield and his solid crossing skills.
Few wing backs are blessed with equal ability going foward as they are in defense, but Brazil star Maicon is on that short list. His marauding runs up the flank offer great support to Brazil's attacking prowess, but he is also a very steady defender with excellent timing and the genuine ability to be at the right place at the right time -- usually when the match is on the line. Maicon's ball skills are also exemplary, meaning he is quite dangerous in the offensive third and can always contribute with goals.