I'm looking to bolster my collection. I'm wondering what the rarest/most valuable comic book that has Harley Quinn in it is. This may just be an opinion thread, so I'm open to any and all suggestions. ...Aaaaaand, GO!

Harley is a relatively "new" character when compared to ones such as Supes or Bats. She first appeared in Batman: The Animated Series, which aired in 1992, so any comics that she is in aren't, in my opinion, going to be terribly valuable in terms of mainstream ones (Her first appearance was in The Batman Adventures comic book, based off of the animated series). If you managed to get a signed copy of an issue or some artwork, then that'll increase the value (obviously). She is most known in the animated series and in her earlier comic iteration for the "Mad Love" comics.

Not knowing anything about Harley Quinn's appearances, I have heard of "Mad Love" (and I've watched the BTAS episode of it!), so I would go with that. So, same as AmazingGamer91.

I couldn't help ya. I did like the little origin story in nu52's suicide squad, but that wouldn't be very rare or valuable.

It's all rare/valuable to me...

Her 2000 solo series is hard to find... and b&m retail-wise, everything Harley Quinn, outside of Batman & Detective comics, will be hard to find. Even online things get snapped up quicker than in-store.

Batman: Harley Quinn (1999 1st Printing) is fairly pricey.

Batman Adventures (1992) #12 is a little bit more than $5 a piece retail wise sometimes.