#10 on the countdown is the Christmas issue of The Long Halloween by Jeph Loeb and Tim Sale.

The conceit of the issue is that the Joker is getting annoyed that the Holiday killer, the serial killer who strikes every month during a holiday, is getting more attention than him...

He begins disrupting the normal flow of Gotham society to get the truth..

In a stunning sequence, he tries to find out if Harvey Dent is the real Holiday killer...

Such gorgeous pencils from Sale. At the end of the issue, after Joker threatens another crook, the crook is killed after the Joker leaves, with Joker's trademark playing cards left behind, leading to Batman thinking that the JOKER is the Holiday Killer.

This is set early in Batman's career, where Batman still thought he could actually stop the crime in Gotham City, but now that people like Joker are showing up, Batman has to wonder whether he actually IS drawing them to Gotham City. Not a happy Christmas for ol' Batman. Such amazing artwork!