5. “Soft Targets” (Issues 12-15)
It seems Gotham has a sniper problem, and whoever it is has been taking shots at public officials with critical results. But when the shooter's identity comes to light, the entire MCU goes into crisis mode. The sniper is such a great villain reveal that's treated with the right amount of tension and build-up. It's the Joker. The sniper is The Joker. And the MCU responds with the appropriate amount of of abject terror.
I've heard "Soft Targets" called the best Joker story of all time and I don't know how much I can disagree with that. It was, for certain, one of the biggest inspirations for the character's portrayal in "The Dark Knight". The Joker in the interrogation room scenes in this are bone-chilling. Plus, we get Detective Patton's defining moment and not everyone survives the arc. "Soft Targets" is tense and unsettling and leaves you on the edge of your seat.
Plus, scariest Joker story I think I've ever read, hands down.

