These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It Was His Sled: Renee Montoya is gay, Two-Face stalked her and she begins to descend into violence and alcoholism as the series comes to a close. Her history is one of the basic premises of 52, a very successful and high-profile series that picked-up after Gotham Central ended, and Gotham Central itself received a lot of press and critical response (Including three awards) for this arc. To many comics readers the series is known as "the one where they outed that chickfromthe cartoon."
Les Yay: In a storyline involving a dead teenager dressed as Robin, members of the Teen Titans are questioned by the police in order to confirm that Robin is alive, as they have no way of determining if the uniform is authentic or a costume. When Starfire arrives, every man smiles and stares, eliciting a disgusted "men" from Detective Romy Chandler. Detective Joely Bartlett smirks and points at Maggie Sawyer and Renee Montoya, "You think?" Maggie even mentions that "You should see Wonder Woman."
Moral Event Horizon: For a while Corrigan does not seem like too bad of a Dirty Cop, no worse than the usual evidence-tampering scum of Gotham, but when he starts torturing other cops and kills Crispus Allen, he stops being small-time petty evil and becomes somebody asking for a bullet.
Tear Jerker: If you can get through this series without reaching for a tissue at least once, you are simply inhuman. Every character experiences loss, defeat and horror that no person should ever have to go through, and then they soldier on and keep going, slogging through more heartache until the end, because everybody knows "It's Gotham."