Papa Wolf: The calm cool type, mostly. When his daughter is kidnapped by terrorists, he walks into a Syrian mosque, reveals himself to be wearing an explosives vests, and tells the congregation that he's willing to kill them all and himself if nobody helps them. What's truly terrifying is how calmly and matter of factly he says it:
"Cool Breeze, Betty Blue. I will count to three. When I get to two, leave the room. The next thing you hear will be an explosion. When that happens, find my daughter. One. Two. God forgive me."
Ranger: Graduated Ranger School and was awarded the Ranger Tab. The show implies that he served in the 75th Ranger Regiment before getting his green beret.
Bob "Cool Breeze" Brown
"How do you think we got in here, you think we were sitting at the 7-Eleven next door? We had to muster up, fly in, parachute in four miles away, hike in here and not get our asses shot off so we can get your asses out! We are your last line of defense sir, we are the cavalry."
Stepford Smiler: His wife is a slut who is sleeping with his superior officer, who is a morally ambiguous jerk who at any point, could send him to his death if he ever felt like it and who gets away with the affair once it becomes public knowledgge. Furthermore, it's implied that he has borderline abusive relationship with his wife and that, while their circle of friends are aware of it, the two are forced to put on a front of being a happy couple for everyone else. Especially after the affair is exposed.
Villainy Discretion Shot: Several episodes in the show's run implied, if not danced around, the fact that Mac was verbally abusive towards his (granted, adulterous) wife Tiffy and that on multiple occasions been physically aggressive towards her when the two fought. None of it is shown on screen however, due to the couple being a pair of Stepford Smilers.
Charles "Betty Blue" Grey
"Yeah... I have a plan. You wanna be some help, or I'm gonna use you for parts? We're gonna take them down."
The Squadette (only partly- she is not a full member of The Unit)
Tom "Dog Patch Zero Six/Blue Iguana" Ryan
"Where your bodybag? Exactly. But each member of the Unit carries their own bodybag. So until you carry one you don't deserve to talk to my men about their code. They sign on to not exist, for them there is no legacy. These men die for each other, not for you or your boss. These men are warriors. You think need to remind them about their code of silence? They answer to a higher code, friend."
The Plan: Runs one when Jonas' daughter is kidnapped and they're investigating in Iraq. He pretends to have a heart attack so that he's injected with a medical radioactive isotope, then lets himself be kidnapped by the terrorists; the isotope allows him to be tracked for a rescue to come.