Personally, I think the Texans by far. Stroud is already a stud, Demeco Ryans seems promising as a motivator and a defensive mind, and their GM, Nick Caserio, probably had the best offseason out of any GM except for Howie Roseman.
I'd also throw the Colts and Rams in. Steichen seems legit and Stafford isn't washed like a lot of people thought.
John Harbaugh is the best head coach in the NFL. Every other HC out there, including the greats like Reid and Belichick, eventually falls to recycling the same failures and nepotism hires in their coaching staff, out of loyalty or just familiarty. But Harbaugh is constantly reinventing his staff and his schemes to best suit his players' talents. He doesn't try to fit a spare peg into a round hole.
He also managed to outcoach Belichick multiple times when it comes to stuff like special teams and rule fuckery. If that isn't impressive, I don't know what is.
The only time I feel he's legitimately choked has been 2019. Every other year, he's been screwed by injuries.