For the fourth consecutive year, the Broncos will enter the season as the heavy favorites due to a stacked roster.
They aren't without question marks, however, foremost of which is Peyton Manning's ability to recapture the form he showed in the first half of the 2014 season.
The Raiders are finally building a nucleus of young talent, but are still years away from serious contention.
1. Denver Broncos
What's changed: Despite a wildly impressive 46-18 record over four years, coach John Fox was dumped in favor of Gary Kubiak, who brought along long-time defensive coordinator Wade Phillips.
Outside of the losses of run-stuffer Terrance Knighton and free safety Rahim Moore, the defensive personnel remains largely intact. The big change is the shift from Jack Del Rio's 4-3 defense to Phillips' 3-4 scheme. Unlike most teams, the Broncos' personnel is already well-suited to the new system.
2. San Diego Chargers
What's changed: The prospect of a franchise move to Los Angeles has Philip Rivers spooked, leaving the Chargers with one of the offseason's most intriguing decisions. Although the team's stated preference is to secure Rivers' future via a long-term deal, Oregon's Marcus Mariota looms as an interesting alternative.
If Rivers stays, he will be throwing to a pair of new targets in veteran wide receivers Stevie Johnson and Jacoby Jones.
3. Kansas City Chiefs
What's changed: Shortly after conceding that a historically inept receiving corps needed to be reconstructed, general manager John Dorsey dumped the trio of Dwayne Bowe, Donnie Avery and A.J. Jenkins. He succeeded in recruiting Jeremy Maclin as Bowe's replacement, reuniting the former Eagles receiver with Andy Reid.
4. Oakland Raiders
What's changed: Gone are interim coach Tony Sparano, offensive coordinator Greg Olson and defensive coordinator Jason Tarver, replaced by Jack Del Rio, Bill Musgrave and Ken Norton Jr.
General manager Reggie McKenzie desperately needs a second consecutive strong draft haul so he can put a halt to Oakland's annual parade of free-agent disappointment.