?

Well I don't know them all. But in pre-flashpoint there has been 2 Black Mask : Roman Sionis and Jeremiah Arkham. In the new 52 it's only a modernised version of Roman Sionis.

As Roman Sionis pre-flashpoint:

• His first appearance is in arc Batman #386-387/ Detective Comics #553 (haven't read)
• He re-appears in Detective Comics #566/Batman #400 (haven't read)
• Then he returns in Batman #484-885. (haven't read)
• You can find him in Detective comics #683-684
• Also in Detective comics #697
• After that he is in "Batman: Bullock's law"
• He has a part in "Batman: War games" (haven't read but isn't considered a notable story even if it's a big arc)
• He plays a big part in "Under the Hood" storyline (haven't read but is considered a gread story and is the return of Jason Todd)
• He also appears in "Batman: War crimes" (haven't read but isn't considered a notable story)
• Finaly in Detective comics #821
• He also appears in a few catwoman vol.3 stories :
  • Catwoman vol.3: Disguises (#6-9)
  • Catwoman vol.3: No easy way down (#10-24)
  • Catwoman vol.3: The one that you love (#38-49)
  • Catwoman vol.3: Backward masking (#50-52)
  • Catwoman vol.3: The replacements (#53-58)
  • Catwoman vol.3: #62
  • Catwoman vol.3: #71
• His life Finaly finished in "Balckest Night" (haven't read yet but is a huge storyline and a must read)

As Jeremiah Arkham pre-flashpoint:

• He first appear in "The Last Arkham" (haven't read)
• He can be seen in the "knightfall" storyline (again a major huge arc in Batman timeline)
• He is part of "Arkham asylium: Living hell" (a very dark story about some inmates - I like it a lot)
• He as a role in "No man's land" (a huge notable arc in Batman's timeline - a must read)
• He is also the main character in "Batman: Life after death" (haven't read)
• Jerimiah Arkham can be seen in the new 52 "Night of the owl"

As Roman Sionis New 52

• Roman Sionis is first seen in the "Court of the owl" arc.
• His main storyline is "Detective Comics: Scare tatics"
• He also appears in a few Catwoman, Forever evil and convergeance

In DCAU related books

• Batman adentures vol.2: Shadows and Masks

In bold are the must read for Black Mask main story, and in underline are stories I believe should also be read to understand the guy better.

I hope this is what you were looking for.

yes thank you

Really dug his part in War Games

Is War Games worth reading?

Not before the stories I put in bold

Which ones that you have read are worth reading the most?

Honestly none of the bold ones. But I will definently read "Under the Hood", "Catwoman", "Blackest Night" and "No man's land".

Naah. Unless you're just the type of person who generally enjoys reading every arc to have the knowledge on it.