Popular Welsh referee flanker Nigel Owens recently picked his all-time dream team, singling these five out for specific praise.
This list doesn't include any Welshman due to his bias.
Nigel Owens ranks the five best players he refereed
#6. Stuart Hogg (Scotland)
Owens said: "How can you fail to be impressed when watching Hogg play. He’s so exciting."
#5. Paul O'Connell (Ireland)
Owens said: "Quite simply he was just an exceptional leader. I have been in charge of games where he pretty much carried his team, whether it was Munster or Ireland, almost on his back and onto victory."
Paul O'Connell of Ireland seen during the Rugby World Cup Pool D match between Italy v Ireland at The Stadium, Queen Elizabeth Olympic Park on Oct 4th 2015 in London - Photo mandatory by-line: Graeme Truby/Pinnacle - Tel: +44(0)1363 881025 - Mobile:0797 1270 681 - VAT Reg No: 183700120 - SPORT - International Rugby
#4. Thierry Dusautoir (France)
Owens said: "My choice as the best skipper I encountered may raise a few eyebrows, but what a captain Dusautoir was. He unfailingly put his body on the line throughout his career — recall the 38 tackles he made when France knocked the All Blacks out of the 2007 World Cup — led by example and understood the game very well.
"Also, he was exemplary in the way he conducted himself.
"There were never any complaints from him over refereeing, not even when borderline decisions went against France. When his team were crushed 62-13 by New Zealand during the 2015 World Cup, he wasn’t tempted to blame anyone.
"He acted as a true leader should act."
England's, Toby Flood fall short of the try line and is taken off the field after France's, Thierry Dusautoir landed on him - Photo mandatory by-line: Jan Kruger / Pinnacle - Tel: +44(0)1363 881025 - Mobile: 0797 1270 681 - VAT Reg No: 768 6958 48 - 150309 - SPORT - RUGBY - RBS 6 NATIONS - England v France - Twickenham
#3. Dan Carter (New Zealand)
Owens said: "There are lots of outside-halves who have been great, but not one who has done it over so many years like Carter.
"Before the 2015 World Cup, some people said he was past his best and wouldn’t make the New Zealand squad for the tournament.
"But for Carter to come back from injury and play as well as he did then is a sign of a special player."
#2. Brian O'Driscoll (Ireland)
Owens said: "Not only is he one of the greatest centres in the history of rugby union but he’s a fantastic man off the field as well.
"O’Driscoll has been a wonderful ambassador for the sport and a real leader. He always respected referees and set the right example for others to follow.
"A legend of the game who conducted himself superbly, on and off the pitch."
#1. Richie McCaw (New Zealand)
Owens said: "If anybody had to pick the greatest player in history, it would surely be a difficult choice between him and Gareth Edwards.
"How McCaw managed to put his body on the line and sometimes the wrong side at rucks for so many years at flanker is incredible."
LONDON, ENGLAND - OCTOBER 31: Richie McCaw of New Zealand lifts the trophy after victory during the 2015 Rugby World Cup Final match between New Zealand and Australia at Twickenham Stadium on October 31, 2015 in London, United Kingdom. (Photo by David Rogers/Getty Images)