Bradley Wiggins (Britain, Team Sky)
Wiggins came to prominence on grand Tours when he finished fourth overall in 2009, only for the Briton to disappoint in 2010 and crash out early in the race last year.
Since then, however, the Team Sky rider has won the Paris-Nice and Criterium du Dauphine stage races and finished third overall in the Vuelta.
A terrific time trialist, Wiggins has also tried to further improve in the mountains this season, putting him in the driving seat to become the first Briton to win the Tour de France.
He can also rely on a very strong team to support him both on the flat and mountain stages.
Cadel Evans (Australia, BMC Racing)
Evans won the Tour last year after two second places in 2007 and 2008, edging out Andy Schleck in the final time trial.
With a team dedicated to his cause, the Australian will start as co-favourite with Britain's Wiggins. He might have to attack in the mountains to gain some time over his Team Sky rival in order to start the final time trial with the yellow jersey on his shoulders.
To do that, Evans will have to force his nature as he is more of the conservative type.
He has not enjoyed the same brilliant results as last year in the lead-up to the Tour but the confidence gained from his 2011 triumph could make up for that.
Denis Menchov (Russia, Katusha)
Never the first name to pop up among the favourites, but the rider who has the best record on grand Tours with a Giro and two Vuelta titles to his name.
Menchov is a good time trialist, and a good climber, a combination necessary to prevail this year.
The Russian, however, does not appear to have a team strong enough to help him throughout a three-week race.
Juergen van den Broeck (Belgium, Lotto-Belisol)
At 29, Van den Broeck has top 10 finishes in all three grand Tours, claiming his best result when he ended up fourth overall in France in 2010.
A good climber who has improved in time trials, the Belgian looks set to finish with the best again after an encouraging fifth place overall in the Criterium du Dauphine earlier this month.
Vincenzo Nibali (Italy, Liquigas-Cannondale)
The 2010 Vuelta champion will start as team leader this year after Ivan Basso built his whole season around the Giro. If Basso really rides as a support rider, Nibali can have high hopes on the Tour as he will also be relying on Polish climber Sylwester Szmyd. (Reporting by Julien Pretot; Editing by Alison Wildey)