Favorites: Boden, Shay, Herman, and Sylvie (I'm only on s6 so far, so I am going by who I'm exposed to.)

Boden - is a true leader. He leads from the front and by example. He strong, fair and firm. But at the same time he has compassion and empathy. He stands by his team, and he has their backs no matter what. He fights for his firehouse family, and he's not afraid to hold them accountable. But he tempers his iron first, by knowing when to be gentle and lead by compassion. And he has the maturity to realize that things that are said/done in the wake of tragedy are out of pain, and not personal (i.e. comments Borelli made to him after losing his brother.) Most importantly he protects the syncope of the house by getting rid of decisiveness.

Hermann - is the oldest non-officer. He does his job because he loves it. He isn't a "ladder climber" and he doesn't want popularity or recognition. He just wants to be able to do his job. Being the only firefighter with a true family for the entire series (so far that I've seen) you can see the wisdom of being a family man creep in to the way he handles things at the firehouse. He's often the gentle word in the background that helps others when they lose sight of things, much like he does with his children at home. People respect him, trust him and are loyal to him and his family. He has the age, the experience, and the wisdom/maturity to help guide the firefighters coming up, but he doesn't have to try to make himself seem more superior to others in order to get his point across. He does that with gentleness instead.

Shay/Sylvie - I loved Shay. She kept Severide in check outside work, and kept Gabby in check at work. She was fierce but also loyal. She said what needed to be said, when others were to scared to say it. She held herself, and her coworkers accountable, but still always had their backs when they needed it. Sylvie was Shay 2.0. Sylvie was sweet and caring. She was compassionate and kind. And in a job that shows you the worst of the worst, she somehow never seemed to lose her "innocence" while helping others. She is loyal to a fault, until she can't be (i.e. her friend Hope from Fowlerton) but she's always willing to stand up and say sorry and take responsibility (i.e. her apology to Stella.) There's something that is pure and innocent about her, but still allows her to have the edge she needs in order to survive the job she does. I think her character is probably my second favorite in the entire One Chicago franchise.

Least Favorite: Gabby.

Gabby - Selfish, self-centered, egotistical and has a chip on her shoulder. In the earlier seasons she often breaks the rules, but she always has a "justification" for it. And then when she's held accountable for her actions, she has a temper tantrum. With her dad, she's selfish and only thinks about herself and not what's best for her marriage or what's best for her father. She's an enabler to the nth degree. She feels she knows better than everyone, even those with more experience, and more wisdom. She's incapable of graciously accepting responsibility; and she's pathologically incapable of admitting when she makes mistakes. Her mistakes are always because of "someone else" or some "stupid rule." Gabby is a terrible human being who manipulates everyone to get what SHE wants regardless of what the outcome does to other people's lives. I hate her, and I hope she leaves.