Let's celebrate this final lead-up to Opening Day by doing what we baseball fans do best -- arguing!
Each day through Friday, I'm going to present my personal top five in the following categories: rotations (today), lineups (Wednesday), bullpens (Thursday) and overall depth and flexibility (Friday). These are power rankings with admittedly little predictive value, because teams will inevitably rise and fall as injuries, trades and unexpected boosts or busts enter the equation. But for now, here are the five clubs with the best rotation alignments at the start of the season.

5. Blue Jays
Toronto had the best rotation ERA (3.64) in the American League last year and nobody seems to have noticed. This group would rank higher on this list if it were clearer who will step up from the farm system should injury be a bigger hurdle than it was in 2016. But the Blue Jays' starting five of Marco Estrada, J.A. Happ, Marcus Stroman, Francisco Liriano and Aaron Sanchez (listed in the planned rotation order, not upside) has made it through the spring healthy and effective.

Sanchez enters the season with no innings restrictions after a dramatic leap from the bullpen to the AL Cy Young Award conversation last season, Stroman stepped up huge on the World Baseball Classic stage, Happ has become one of the most effective lefty arms in the game, Estrada has a 127 ERA+ over his last two seasons and will be pitching for his next contract, and Liriano's reunion with Russell Martin last summer helped him post a 2.92 ERA and 148 ERA+ in 10 games for the Jays.
4. Cubs
The World Series champs' rotation had the only sub-3.00 ERA in baseball last season, and that came despite a regression from Jacob Arrieta's 2015 National League Cy Young Award-winning season. With Arrieta in a contract year and Jonathan Lester, Kyle Hendricks and John Lackey all back, there's a good chance the Cubs will maintain an elite starting set -- even with Jason Hammel, who gave this club 166 2/3 mostly quality innings, having departed in free agency.

Of course, maintaining an abnormally low .252 opponents' batting average on balls in play could prove impossible, and the workload watch after last year's deep run could lead to some difficult decisions for manager Joe Maddon. Whether Brett Anderson, Mike Montgomery, Eddie Butler, etc., provide adequate, durable insurance remains to be seen.
3. Nationals
This was definitely a deeper group before the Adam Eaton trade, when Lucas Giolito and Reynaldo Lopez were still aboard as insurance. Still, Austin Voth, A.J. Cole and Erick Fedde are among the arms that could impact the Nats when in-season needs inevitably arise. Washington hopes they don't arise on account of another health issue involving Stephen Strasburg, who we know is no lock for 200 innings. Additionally, reigning NL Cy Young Award winner Max Scherzer dealt with a weird knuckle injury that forced him to use a new fastball grip in camp.

But Strasburg (116 ERA+ in 2016) and Scherzer (141) are both operational in front of the underrated Tanner Roark (148), which is a great start. It will be interesting to see what strides Joe Ross (122) takes if he's able to pitch a full season for the first time, and a bounceback season from Giovany Gonzalez (92) -- the lone lefty in this group -- might be essential to justify this top-five rank.
2. Indians
The good thing about the Indians getting within one win of a World Series title with 2 1/2 starters (Corey Kluber, Josh Tomlin and nine fingers' worth of drone boy Trevor Bauer) is that the return of Carlos Carrasco and Danny Salazar from their 2016 injuries makes this group look great. The downside is that the Tribe had to ride Kluber and Tomlin pretty hard in October, and we'll see what lag effect, if any, that has in the new season. Carrasco's right elbow swelling in Spring Training and the unknown as to whether Salazar's flexor tendon strain from last season will be a precursor to a bigger problem are other potential issues for a club that took a depth hit with Cody Anderson's spring Tommy John surgery.
Anyway, take all these guys at face value and you've got a stellar starting five for the defending AL champs. If the general population wasn't already convinced Kluber is in the elite starters' tier, his October output ought to have clinched it.

1. Mets
As distracting as the Tim Tebow experience or Yoenis Cespedes' bulging biceps or the center-field questions might have been, the most important element of the Mets spring camp is that their deep rotation has gotten through mostly unscathed.
Noah Syndergaard (158) has serious Cy Young potential in his second full season. Jacob deGrom, coming off ulnar nerve surgery, has had an especially encouraging camp as he tries to build off his terrific 2014-16 portfolio (combined 138 ERA+). Matt Harvey's velocity is coming back after the expected (and literal) slow start following thoracic outlet syndrome surgery. Robert Gsellman and Seth Lugo were huge for this club when injury struck last year, and now, with Gsellman likely in the No. 5 spot and Lugo coming off a strong showing in the Classic, they add to the overall allure of the Mets' outlook. No telling if Zack Wheeler, coming back from 2015 Tommy John surgery, will join the rotation at some point or pitch out of the 'pen or if Steven Matz's elbow irritation will be a big deal, but the depth here is undeniable.
Honorable mention: The Giants have a strong argument here with Madison Bumgarner, Johnny Cueto, Jeff Samardzija, Matt Moore and a home park that suppresses runs. Player Page for Matt Cain's spring didn't inspire much optimism, but Ty Blach looks like a worthy replacement. … You could very easily put the Dodgers here on the might of a healthy Clayton Kershaw and the (eventual) upside of Julio Urias, but let's see how things develop with the rest of that group. … Where are the Red Sox? I'll answer your question with a question: Where's David Price? Until he's back in action and we are certain his left elbow issue won't be a limiting factor once he's on the mound, it's hard to back Boston as a top-five rotation on Opening Day, even with the fearsome twosome up top (Rick Porcello and Chris Sale). That group already had some back-end questions before Price went down.