Ben Youngs: The 22-year-old England scrum-half could be the player of the tournament, but needs to recapture the electric form he showed against Australia home and away last season. The Leicester youngster, who has won 12 England caps, has been injured but was passed fit for England's first game against Argentina.
Richie Gray: The mobile 6ft 9in lock adds another dimension to Scotland because of his ability to do what's expected of a second row, plus he gets around the paddock in defence and attacks like a back row player. He's only just 22 and only has 12 caps but is improving rapidly as he matures physically.
James Hook: The versatile Hook showed in the warm-up games against England and Argentina that he should start at fly-half for Wales. The Perpignan-bound player, who has played centre and full-back for his country, has the ability to make things happen when he's got the ball in his hands, and playing at 10 he will get more chances.
Sean O'Brien: The European player of the season after a storming campaign with Heineken Cup champions Leinster, producing consistent performances all season. The Ireland back rower seems even bigger than his 6ft 2in, 16st 13lb frame and is a superb ball carrier who very rarely fails to get go forward. He also gets all over the field of play, both offensively and defensively.
Vincent Clerc: The experienced France and Toulouse winger always seems to be in the right place at the right time to score, although he is also more than capable of creating scores in tight spots and not just running them in. The 30-year-old has 25 tries in 50 caps and a strike rate of a try every other game is world class.
Sergio Parisse: The Stade Francais star is a contender for the best number eight in the world. Parisse, who turns 28 three days after the tournament kicks off, already has 79 Azzurri caps and never seems to have a bad game. A mobile 6ft 5in and a fine footballer, he always leads by example, which can't always be easy playing for Italy.
Quade Cooper: This guy could as easily lose the World Cup for the Aussies as win it - he is without doubt the most mercurial player in world rugby right now. The 23-year-old fly-half guided the Queensland Reds to victory in the Super 15 and has earned 28 caps since seizing the Wallaby jersey.
Kieran Read: The Crusaders man does everything a number eight should do and makes it all look so easy - he is a player who is incredibly effective in all areas of the game. New Zealand boss Graham Henry held his breath when the 25-year-old, 6ft 4in back rower injured his knee in the final Tri-Nations game, but he will be fit for the knockout stages of the tournament.
Fourie du Preez: Four years ago he was the best scrum-half in the game, helping guide South Africa to World Cup glory in France. The 29-year-old Bulls star is still very influential, bossing those Boks forwards, and although last time out against the All Blacks he didn't look that fit, he will get better as the tournament goes on.
Felipe Contepomi: The Argentina fly-half is an old stager who has been around a long time. The 34-year-old former Bristol and Leinster player, a qualified doctor, will be hoping to inspire his team-mates to another glorious World Cup after their third place in 2007. He has racked up 562 points in 71 Tests.
Soane Tongahuia: It will be interesting to see if the giant Northampton loose-head prop can have the same impact for Tonga as he does for Saints. He is a very mobile 6ft 3in and 20st, and is one of the most destructive ball carriers in European club rugby. He is also a powerful scrummager if he can bring his power and huge frame to bear.
Alesana Tuilagi: I love watching the Samoa winger play - every time he carries the ball you know there's going to be a big impact, and he scores good tries. At 6ft 1in and 18st 6lb the 30-year-old Leicester powerhouse, brother of England's Manu, combines the size and power of a prop with the pace and finishing ability of a very fine winger.