|The Padres added a ton of talent this winter (UT San Diego)|
Boston Red Sox
The Red Sox added a lot of punch to what was a woefully thin offense last year, inking two of the market's top hitters in Pablo Sandoval and Hanley Ramirez. They also overhauled their rotation, trading for Rick Porcello and Wade Miley in addition to signing Justin Masterson. After losing 91 games and finishing last in the AL East in 2014, Boston's back to being one of the best teams in baseball.
An 89-loss team last year, the youthful Cubbies enter 2015 on the brink of contention. Their abundant young talent is about to bloom, and they brought in a good deal of veteran talent by landing Jon Lester, bringing back Jason Hammel, and trading for Dexter Fowler as well as Miguel Montero. Look for Chicago to make a big leap forward this year and challenge St. Louis for the NL Central crown.
Chicago White Sox
The White Sox made several good moves this winter that should at least get them over .500 after dropping 89 games a year ago. The Jeff Samardzija trade gives them a formidable top of the rotation alongside Chris Sale and Jose Quintana, and the offense should be better with Melky Cabrera and Adam LaRoche on board. I don't like the White Sox as much as their crosstown rivals, but both teams project to be relevant for the first time in a while.
San Diego Padres
No team upgraded more this offseason than the Padres, who signed James Shields last week to cap their busiest winter in recent memory. Shields should thrive in Petco Park and the offense looks dynamite after trades for Matt Kemp, Justin Upton, Wil Myers, Derek Norris, and Will Middlebrooks. Yes, their outfield defense looks terrible and their infield might be atrocious, but San Diego should be able to take advantage of a relatively weak NL West outside of the Dodgers.
Toronto Blue Jays
The Blue Jays committed to their win-now approach by signing Russell Martin--a top-five catcher--and trading for Josh Donaldson--one of baseball's best players period. Both should benefit from the homer-friendly conditions in Toronto and will join with Jose Bautista, Edwin Encarnacion, and Jose Reyes to form an incredibly lethal lineup. The Jays have underachieved the past two years, but I think this is the year they finally break through and make some noise in the AL East.
Honorable Mentions: Houston Astros, Los Angeles Dodgers, Miami Marlins