Oliver Queen (Arrow)
After surviving all those things on Lian Yu, it'll be hard for anyone to not develop an abnormally high degree of resistance to physical pain. Still, it wasn't clear how high Oliver's was until he got a sword pushed clean through him and was kicked off a mountain by Ra's Al-Ghul.
Mad Sweeney (American Gods)
Underneath all that bravado is an old soul who actually cares even if he doesn't show it all that often. But he also has the word "mad" in his name, which should give you an idea into how vicious he is in a fight, and he can take almost all you can throw at him.
Spartacus (Spartacus: Blood And Sand)
Spartacus was the spark that ignited the war between the slaves and the Roman Empire, thankfully his time in the arena hardened him enough to not care about the world of hurt the empire had in store for him.
Misty Knight (Luke Cage)
Misty has been through a lot in a very short time. She made a few superpowered friends in that time, but she also lost her arm as a parting gift from Bakudo. She also had to start fighting enemies that were several steps above the usual miscreants she comes across as a detective. Not surprisingly, she got the daylight kicked out of her a number of times, but she got back up every time.
Hilda Spellman (Chilling Adventures Of Sabrina)
The amount of cruelty Hilda has suffered at the hands of her sister is extremely disturbing, but after being killed in so many ways, and so many times, Hilda has undoubtedly grown used to the pain that comes with those violent deaths.
Alaric Saltzman (Legacies)
Alaric has lost a lot and has been through some really convoluted periods in his life. But, before he was turned into a supernatural vampire killer (and then back to human again), he was an everyday person being who proved quite adept at holding his own against vampires. It goes without saying that he was outmatched most of the time, which is probably why his resistance to pain is many times greater than a regular person's.