Tom Verducci: The Twins. They have a good core of rising young position players, but need to supplement it with one or two proven pitchers. They should be aggressively in on Darvish, Jake Arrieta and Alex Cobb.
Jay Jaffe: The Giants. If they're going to compete with the powerhouse Dodgers and the resurgent Diamondbacks and Rockies, they have a lot of work to do. They need significant help at third base, all over the outfield (where Denard Span and Hunter Pence are shadows of their former selves) and the rotation. At best, Stanton and Ohtani would fill two of those holes.
Stephanie Apstein: The Angels. The Justin Upton deal was a good start, but they need to put a reasonable team around Mike Trout and then try their luck in the playoffs.
Jack Dickey: Presumably the Phillies, having hired a manager for the future (Gabe Kapler), are ready to advance to the next phase of their rebuild. To do that, though, the team should surround useful youngsters like right-hander Aaron Nola, first baseman Rhys Hoskins, and hot-prospect shortstop/third baseman J.P. Crawford with a veteran starter or two. Keep an eye, too, on the Brewers, who finished 86–76 in 2017 despite essentially being a collection of spare parts. Adding Darvish or Jake Arrieta would do them good.
Jon Tayler: Thanks to an unexpected season that brought them within one game of a playoff spot, the Brewers are suddenly contenders when they were supposed to be amid a painful and protracted rebuild. But all the youth flourished earlier than expected, and Milwaukee has a chance to make real moves to make the team a real threat in the NL Central. So the Brewers should go into Winter Meetings ready to do just that. Pitch Jake Arrieta on staying in the division and on the benefits of all-you-can-eat bratwursts. Try to get a better second baseman than Eric Sogard. See if Jonathan Lucroy is interested in coming back to catch. Learn from the Pirates, who let their window close with nothing but three wild-card games and a Division Series appearance to show for it. Act now, knowing that the future is still bright.
Gabriel Baumgaertner: The Giants look like they're trying to remedy the problems that sunk them in 2017, but they shouldn't be investing their future in Giancarlo Stanton. Instead, they should try and figure out third base by engaging Tampa Bay for Evan Longoria, see what the Reds want for Billy Hamilton and what Toronto would need for Kevin Pillar. The farm system is bad and they'll bankrupt themselves if they sell the house for Stanton, who will regress in AT&T Park even if he bolsters a currently dreadful lineup. Just about everything went wrong for the Giants last year, and they need to make small acquisitions—the way Brian Sabean did in compiling their 2010 World Series team—instead of selling the house for a big name.
Connor Grossman: I’m a big advocate for the best teams consistently trying to get better, avoiding the complacency that can easily set in after a World Series run. With that in mind, both the Dodgers and Astros should be the most aggressive. Both teams had weaknesses exposed in October, with Houston standing to improve their relief depth and Los Angeles in need of a spark in its starting rotation.
The idea of Ohtani and/or Stanton joining the Dodgers should strike a boatload of fear into the rest of the National League. The path to the Fall Classic just got that much more difficult.