"These were happy and glorious Games," - IOC president Jacques Rogge at the closing ceremony.
"I did everything I wanted to. I finished my career the way I wanted to," - American swimmer Michael Phelps after retiring with 18 gold medals.
"I hope that this medal inspires the kids at home to put down guns and knives and pick up a pair of trainers instead," - Erick Barrondo, winner of Guatemala's first-ever Olympic medal with silver in the men's 20-kilometre race walk.
"I'm now a legend. I'm also the greatest athlete to live," - Jamaican sprinter Usain Bolt after retaining his 100 and 200 metre titles.
"Bolt was good but Rudisha was magnificent - it was the performance of the Games, not just track and field," - London 2012 head Sebastian Coe about Kenyan David Rudisha's world record win in the 800 metres.
"I am more worried about being a good person than being the best football player in the world. When all this is over, what are you left with?" - Barcelona and Argentina forward Lionel Messi.
"We're talking about a great generation of footballers. This is a great era for Spanish football," - Spain coach Vicente del Bosque after his team won the European championship.
"I'm sure he's smiling from up there that someone has finally managed to do it from Britain. I just hope I can see another British player in my lifetime win a Grand Slam," - Andy Murray after becoming the first British man since Fred Perry in 1936 to win the US Open.
"I really think a champion is defined not by their wins but by how they can recover when they fall. I have fallen several times. Each time I just get up and I dust myself off and I pray and I'm able to do better," - Serena Williams after coming back from a life-threatening illness to win the Wimbledon, Olympic and US Open titles.
"I never got this far in my dreams," - Bubba Watson after winning the Masters in a dramatic playoff with Louis Oosthuizen.
"He's got all the talent in the world to do what he's doing. And this is the way that Rory can play," - Tiger Woods about Rory McIlroy after the Northern Irishman won the US PGA Championship by eight shots.
"This isn't about bragging rights. This is a lot bigger. This is about a team, an organization being named world champions," - New York Giants quarterback Eli Manning after winning his second Super Bowl, one more than his older brother Peyton.
"It is our responsibility to protect player safety and the integrity of our game and this kind of conduct will not be tolerated," - NFL commissioner Roger Goodell after announcing a range of penalties following revelations of the New Orleans Saints cash-for-hits scheme.
"It's about damn time," - Miami Heat forward LeBron James after winning his first NBA title.
"We're all so proud of LeBron. When you get to know LeBron, you don't understand why he was such a lightning rod for the criticism," - Miami Heat coach Erik Spoelstra.
"It sounds cheesy, but your whole life is for this and the reason I got into cycling as a kid was today," - Bradley Wiggins after becoming the first Briton to win the Tour de France.
"There comes a point in every man's life when he has to say, 'Enough is enough.' For me, that time is now," - Lance Armstrong, announcing he would not contest the doping charges against him and his former team.
"The evidence shows beyond any doubt that the US Postal Service Pro Cycling Team ran the most sophisticated, professionalized and successful doping program that sport has ever seen," - statement from US Anti-Doping Agency chief executive Travis Tygart.
"People were not even mentioning us when they were talking about the championship, but I think the most important thing was that we always kept believing," - Sebastian Vettel after winning his third successive Formula One world title at age 25.
"If the sword breaks, attack with the hands. If they cut off your hands, push the enemy with your shoulders, even with your teeth," - Championship runner-up Fernando Alonso about his battles with Vettel.
"This is something everyone's dreamed of for their whole lives and this city's dreamed of for 45 years," - Los Angeles captain Dustin Brown after the Kings won the Stanley Cup for the first time.
"We are not prepared to open another season until we have a new collective bargaining agreement," - NHL Commissioner Gary Bettman, signalling the start of another player lockout.
"Where else in the world do you get the opportunity to basically kill someone with two bouncers an over? Or try, legally," - South African fast bowler Dale Steyn.
"Cricket is not like a government job where retirement age is fixed at 60. A cricketer can retire at 30 or 60; it's up to the player," - India's evergreen batsman Virender Sehwag.
"It's for other people to judge whether we are the greatest team or not - or if we are a great team," - New Zealand coach Steve Hansen after another dominant season by the All Blacks.
"Today, we witnessed the arrival of a new generation of Welsh rugby heroes - a group of players who have equalled the success of those great Welsh teams of the past," - Wales First Minister Carwyn Jones after Wales won the Grand Slam and the Six Nations.