We are currently running an auction on our goldenapplecomics eBay account for Batman The Killing Joke 1st, 2nd, 3rd, 4th, 5th, 6th and 7th print. Its a cool set and early printings can be determined by the color of the title on the cover.
1st Print = Neon Green
2nd Print = Pink
3rd Print = Bright Yellow
4th Print = Light Orange
5th Print = Blue
6th Print = Neon Orange
7th Print = Light Yellow
8th Print = Light Blue
9th Print = Red
10th -13th = yellow - slightly different colored cuff links on Jokers sleeve
14th = Dark Green
There are also UK editions published by Titan Books and a Deluxe Edition HC.
If you haven't read Batman The Killing Joke we highly recommend it. It is a classic Alan Moore story and Brian Bolland's art is incredible.