Martha as part of Superwho/Superwood always makes me happy. Sam and Martha would circle each other warily and then find common ground in their compassion, intelligence… and end up kvetching about feeling like they’ve always got to prove themselves to Oblivious People. They’d get on famously and end up with private jokes and wordless communication through sighs and eyerolls (which eventually includes Cas as well). This makes Jack snippily territorial of Martha’s attention and expertise on occasion. He gets revenge on Sam by regularly tweaking Dean’s ego, which inevitably means Sam has to wade in.
Though things smooth out, Dean’s suspicious nature (especially upon finding out Jack’s immortal) means Jack ends up working mostly solo, with Martha and occasionally Mickey acting as liasons to keep a relative peace.
Once they hit the Boss Level, however, everyone puts their bullshit aside. Dean and Cas save Jack’s ass, Jack takes a gutting for Sam and Mickey, and when it’s all over, Martha keeps everyone from stepping in Jack long enough for him to pull back together.
They all convene for burgers and beer.
It’s still Sunday! Ask or Submit your SuperWood, SuperWho or SuperWhoLock headcanons and I’ll post them.