ESPN.com celebrates its 20th anniversary this week. We'll be highlighting some of the top teams, athletes and moments that characterized greatness in sports from 1995 to 2015.

Michael Jordan, Michael Phelps, Serena Williams, Tiger Woods -- which athletes defined the pinnacle of sports over the past two decades? Our staff chose the following athletes as the best of the best. Athletes were limited to those whose careers existed or their crowning achievements occurred within the last 20 years.

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He is still shy of 30, but if Crosby never stepped foot on the rink again, he'd still be a Hall of Famer. He passed the century mark in points in four of his first five seasons. In his third season, he led the Pittsburgh Penguins to a Stanley Cup finals berth. In his fourth, he hoisted the Cup himself. The following February at the 2010 Vancouver Olympics, he scored the gold medal-winning goal in overtime on home soil against the United States. And when he played his 600th NHL game this February, he had accrued 825 career points. The only players with more through their first 600 games? Wayne Gretzky (1,451), Mario Lemieux (1,215), Mike Bossy (921), Peter Stastny (901), Bobby Orr (864), Jari Kurri (848), Bryan Trottier (830) and Denis Savard (827). Hall of Famers, all.

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Oh, that swing. It was quick. And compact. And smooth. And masterful enough to log 73 home runs in a season and 762 in a career, both major league standard-setters. Bonds would go on to become one of the faces of baseball's darkest eras -- his milestones and career always, in some way, connected to performance enhancement. But on Aug. 7, 2007, Bonds passed baseball great Hank Aaron to stand alone as the all-time home run king. And there is at least one person for whom that is just fine. Said Bonds on the night the record fell: "This record is not tainted at all, at all."

No. 18: Mia Hamm

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"When Mia came along, our game was nothing and nowhere," North Carolina's longtime women's soccer coach Anson Dorrance once said. "When she left it, it was something and significant." Yes, when Hamm retired in 2004, she left her mark. Her 158 goals in 275 matches stood as an all-time U.S. best until June 2013. She won a gold medal in Atlanta in 1996, then again in Athens in 2004. Oh, and in between, there was that Women's World Cup victory in 1999. She was something and significant, alright.

No. 17: Floyd Mayweather Jr.

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Mayweather has stepped into the ring 47 times since 1996, and 47 times he has emerged victorious. But 47 times he faced an opponent not named Manny Pacquiao. The bout boxing fans the world over wanted to see was the one fight they never could ... until May 2, 2015. Until then -- and maybe after, too -- Mayweather's perfect record remains one of the Sweet Science's sweetest feats.

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His name is Bolt, which is appropriate, because he does. He. Flat. Out. Bolts. It took the Jamaican sprinter an Olympic-record 9.63 seconds in August 2012 to take home the gold in the Summer Games' marquee track event, the 100 meters. In true Bolt form, he repeated his unprecedented 2008 Beijing feat, winning the 100, 200 and 4x100 relay in a single Games. And in truest Bolt form, he crossed the finish line in London wagging his finger before taking a high-fiving victory lap around the track.

No. 15: Brett Favre

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When your name is Brett Favre and you play in a cathedral called Lambeau Field, history nearly writes itself, even when you're not actually in Lambeau. There was the quarterback's 399-yard game, played in Oakland, California, just one day after his father's unexpected death in December 2003. Before that, he threw two touchdowns and ran for one more in his Super Bowl-winning performance in January 1997. But there was nothing quite like Favre in the frozen tundra, where he started his career 39-6 in sub-40-degree outings. Turns out a boy from Mississippi found his way to Wisconsin, and magic happened.

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If there is such a thing as a quiet five-time NBA champion, Duncan is it. Who else, after all, could earn a nickname as unassuming and flashless as "The Big Fundamental?" But for 17-plus seasons, he has anchored the San Antonio Spurs -- the league's most consistent franchise this century -- not once missing the postseason. That means there is an entire generation of San Antonians that knows nothing but Duncan's penchant for sustained excellence. And for those convinced outlet passes, layups and rebounds do not a highlight reel make, Duncan's best asset as a player just might be his ability to elevate the four Spurs taking the court with him. And that a (five-time) champion does make.

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Who is Lance Armstrong? Is he the Tour de France legend who beat cancer and captured an unprecedented seven consecutive yellow jerseys from 1999 until 2005? Or is he merely cycling's exiled ex-star living in self-made purgatory, who lost those same jerseys (at least in the history books) amid a haze of performance-enhancing drugs and elaborate lies? Perhaps he is both -- at once the sport's most successful competitor and most abhorred history-maker.

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"I have seen the player who will inherit my place in Argentine football, and his name is Messi," said Diego Maradona, the Argentine great himself. And in January 2013, after claiming his fourth consecutive Ballon d'Or, Messi left little doubt. If there ever was such doubt to begin with. Because with Messi, it's another day, another broken record. Case in point: Just this month, the Barcelona forward tallied his 32nd career hat trick -- the most in Spanish football history. Don't blink or you'll miss another.

No. 11: Shaquille O'Neal

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The Big Aristotle. The Big Cactus. The Big Shaqtus. Shaq. It was almost as though no one name was big enough to capture all 7-foot-1, 28,596 points worth of the four-time NBA champion. Nor one team. In all, O'Neal called six cities home, but he spent eight seasons -- by far his longest stint -- with the Los Angeles Lakers, much of it on a love-him-today-hate-him-tomorrow roller-coaster ride with Kobe Bryant. Still, they -- and we -- will always have their Game 7, 2000 Western Conference finals, comeback-sealing alley-oop. O'Neal's post-shot, arms-to-the-heavens, mouth-agape celebration was pure joy. In other words: pure Shaq.

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Once upon a time, a fourth-grader from Kalamazoo, Michigan, told his teacher he'd be a New York Yankee. And for 20 years, he was. He won five Fall Classics in Bronx pinstripes. He sent his 3,000th hit into the left-field stands, a home run. And in his last-ever trip to home plate in Yankee Stadium, he launched a first-pitch fastball into right field, heading into that Yankee sunset with a walk-off hit. The end. Was it a fairy tale? No, just Derek Jeter's Bronx tale.

No. 9: Michael Phelps

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The summer of 2008 belonged to a 23-year-old and his swimming pool. Because that August, Phelps went to Beijing, collected eight gold medals and left China the most decorated gold medalist in Olympics history. In all, he has reached the Olympics podium on 22 occasions in his career, and a staggering 82 percent of the time, he did so with gold in hand.

No. 8: Kobe Bryant

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Forget, for a moment, April 2013, when Bryant collapsed to the court, his Achilles ruptured and his season over. Look past March 2014, when the Lakers shut Bryant down again, this time with a fractured knee. Pay no mind to January 2015, when the L.A. institution succumbed to season-ending shoulder injury. Before all that, there was a shooting guard so singularly focused on winning, he returned to Philadelphia for the 2001 NBA Finals, telling his hometown the Lakers would "cut their hearts out." There was a Laker who dropped 81 points, second most for a single game in NBA history -- on a night in January 2006. And there was a Bryant who brought five titles (in 11 seasons) to Hollywood.

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Peyton Manning? "[He's] the best quarterback I've coached against," says Bill Belichick, who knows a thing or two about Canton-bound signal-callers. Manning's 530 touchdown passes are an NFL record. His 55 in 2013 alone are also. He has accrued more than 4,000 yards passing in 14 seasons, and that too is an NFL standard. And he stands with Favre as the only quarterbacks in NFL history to beat all 32 teams. Manning doesn't just win. He wins ... and wins ... and wins ... and wins.

No. 6: Serena Williams

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There is dominant, and then, there is Serena Williams. She is the No. 1 women's tennis player in the world yet hasn't lost to Maria Sharapova -- second-ranked and no slouch herself -- in 11 years. She has emerged victorious in 23 of her past 25 matches against top-10 players. And with 19 Grand Slam titles to her name, she has Steffi Graf's record (22) in her sights, with no sign of slowing down. "I feel like I'm doing everything better," the 33-year-old says. "Thirty is the new 20, I guess."

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"Personally, I've gotten used to Roger breaking my records," Pete Sampras once said. What record, after all, has Federer not chased? He eclipsed Sampras' 14 Grand Slam titles in 2009, then tallied two more for good measure. He spent 302 weeks atop the ATP rankings, 16 more than Sampras, his closest competitor. And yet, there remains one record Federer hasn't yet claimed outright: He has matched, but not surpassed, Sampras' seven Wimbledon championships. Not even Federer, immortal though he once may have seemed, can fend off age and injury ... But there is one who believes the Swiss has one more left in him, and who knows better than Pete Sampras?

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6: The draft round in which the New England Patriots tapped former Michigan quarterback Tom Brady 15 years ago; 3: The times he has earned Super Bowl MVP honors; 13: The years separating Brady's first Super Bowl win -- a 20-17 victory over the St. Louis Rams on Feb. 3, 2002 -- and his fourth, just two months ago; 0: The number of quarterbacks with more Super Bowl wins to his name. Only Joe Montana and Terry Bradshaw join Brady as four-time champions, and that, we think, is some all-time company.

No. 3: Tiger Woods

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On June 15, 2008, Tiger Woods stood 15 treacherous feet away from Torrey Pines' 18th hole. One shot shy of U.S. Open leader Rocco Mediate, it was birdie or bust for the world's best golfer on Father's Day. He pulled his putter back. He struck the ball. The ball nearly lipped out, and then:

"Expect anything different?" NBC announcer Dan Hicks said.

The ball found the hole. Of course, it found the hole. It might seem like an eternity ago -- seven years is an eternity in the life of an athlete -- but for a moment, there was no surer thing than Woods. He collected 14 majors in 12 years' time, and even if there are no more to come, even if today's Woods is but a shell of the early-aughts era legend, we saw Tiger prowling the greens in red and black. So we saw greatness.

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When the Cleveland Cavaliers selected hometown kid James with the first pick of the 2003 NBA draft, we were all witnesses. When the King took his talents to South Beach seven years later, we were all witnesses. And four years after that, when James announced he was coming home, we were all witnesses. There were five championship appearances, two titles won and four MVP honors in between. He was beloved, reviled, then beloved again, and all before he was 30.

No. 1: Michael Jordan

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The tongue. The clincher. The flu. The fax. Yes, the '90s belonged to His Airness -- and every last moment he left in his iconic wake. Jordan won back-to-back-to-back championships starting in the 1995-96 season -- and as many Finals MVPs -- but above all else, he gave rise to an entire generation that just wanted to be like Mike. "I think he's God, disguised as Michael Jordan," Larry Bird once said ... along with just about every other sports fan who had the privilege to watch Jordan elevate the game of basketball to an art form.

Captions written by ESPN The Magazine writer Hallie Grossman.