Totally impossible to say since this year's season hasn't started yet. But others will offer biased opinions that may or may not be true come September/October.
In 2014, I believe that the LA Dodgers will be the most successful team in the National League and the New York Yankees will be the most successful team in the American League.
I think that the Detroit Tigers are the best team in baseball. They may not be the most successful, but they are the best. A member of the Detroit Tigers has won the AL MVP the past three years (Justin Verlander-2011, Miguel Cabrera-2012, Miguel Cabrera-2013). Miguel Cabrera (first baseman) is the best hitter in the entire MLB. Their second baseman Ian Kinsler is a two time 30/30 hitter (that means he had at least 30 home runs and 30 stolen bases in on season). The team is full of future stars like Jose Inglesieas, Nick Castellanos, Steve Lombardozzi, and Austin Jackson. Their designated hitter, Victor Martinez and their right fielder, Torii Hunter bring a great veteran presence and they still have a lot of life left in them.
The Tigers Pitching staff is Amazing. Their ace, Justin Verlander, was the rookie of the year in 2006, won the AL MVP in 2011, won the AL Cy Young award (best pitcher) in 2011, and threw two no-hitters. Max Scherzer, their second started, won the AL Cy Young award in 2013 and lead the MLB in wins. Their third pitcher, Anibal Sanchez, threw a no-hitter and lead the AL in ERA (earned runs average). their other two starters, Drew Smyly and Rick Porcello are full of potential.
They also have a great bullpen. Hard throwing young gun Bruce Rendon, great middle reliever Al Alburquerque, One of the best relievers in the MLB in Jaba Chamberlain and probably the games best closer Joe Nathan (now that Rivera retired.
Overall best team.
I'm going to say the Cardinals and Athletics because they have the smartest front offices in the whole league. They know how to sign advanced statistic players.
Redsox their the defending champs, got a good mix of veterans and young players, and a solid closer
Who are the best players on their team and why they are so much better than the rest