While the past 20 years have been filled with success, it really is tough to narrow it down to the absolute best teams. With that said, I believe that there are five worthy teams to be considered. 
5) 2004 Patriots 
The reigning Super Bowl champions had just won their second title in three seasons, and Tom Brady was really coming into his own. While the defense was still great, the addition of Corey Dillon made the offense lethal. New England went on to crush Peyton Manning’s Colts 20–3 in the first round of the playoffs, followed by a 41–27 win over the Steelers. In the Super Bowl, the Patriots defeated the Philadelphia Eagles 24–21, as Deion Branch won MVP of the game.
4) 2011 Bruins
One of the grittiest teams in Boston sports history, the 2011 Bruins were on a mission all playoffs long. Goalie Tim Thomas stood on his head for the duration of the postseason; stealing wins for the Bruins left and right. In order to eventually win the Stanley Cup, they had to win three seven game series’, including game seven of the cup finals. Zdeno Chara and Patrice Bergeron are about as deserving champions as they come, and really excelled in 2011 in order to propel Boston to its lone championship of the 2000s. 
3) 2008 Celtics
Depending on your favorite sport, the 2008 Celtics are perhaps the most exciting Boston team of the past two decades. After a 22 year drought without a championship appearance, Danny Ainge was eager to find a way to bring in proven talent. He had his eye on Kevin Garnett long before 2008, but finally saw an opportunity to not only trade for him in the short team, but to also get him to stay for the future. In order to that, he would need another star; which was how Ray Allen came into the picture. The two of them along with Paul Pierce allowed the Celtics to excel under Doc Rivers, going on to win their seventeenth championship over the Los Angeles Lakers. 
2) 2004 Red Sox
In 2003, the Red Sox lost to the Yankees in the American League Championship Series in heartbreaking fashion. After a strong comeback year in 2004, Boston once again found itself a tough spot. Down 3–0 with two outs in the home half of the ninth inning, Dave Roberts took first base as a pinch runner. Everyone in America knew he was stealing second, yet he was able to slide in safely past Derek Jeter’s tag. After a culmination of clutch performances from David Ortiz, Curt Schilling, Johnny Damon, and the rest of the team, the Red Sox pulled off the greatest come from behind series victory of all time. Boston went on to sweep the St. Louis Cardinals and win its first championship in 86 years. 
1) 2014 Patriots
Some may consider this to be an unpopular pick, but I believe the 2014 Patriots are the best team in modern Boston sports history. The year started shaky, but then Brady seemed as rejuvenated as ever by week five. 2014 is realistically the only season ever that Julian Edelman, Rob Gronkowski, and Danny Amendola were all healthy and in their primes. Aside from them, New England’s defense was right up there with the best of the Belichick era. Dont’a Hightower, Chandler Jones, and Jamie Collins made up what was probably the best line-backing corps in the NFL at the time. As far as the secondary goes, Darrelle Revis and Brandon Browner were the cornerbacks, while Devin McCourty and Patrick Chung were the safeties. It was truly the perfect balance between offense and defense, which was going to be needed in order to take down the reigning champion Seattle Seahawks. Brady pulled off yet another incredible comeback, erasing a ten point deficit in the fourth quarter … he also received some help from a Malcolm Butler game-saving interception.