Also, Sierra (King's Quest, Space Quest, Gabriel Knight, etc), Knowledge Associates (lots of ancient Edutainment IP, including Mario Teaches Typing and Mario is Missing!), Davidson (Math Blaster and other Edutainment IP), and more. Activision was a massive M&A shop of classic PC games history.
Quake, Wolfenstein, elite force*
*may have paramount cbs locking that up but Raven comes back to the family with id now
They already owned those when they bought Zenimax, who bought id (except for the Trek games).
Not HHGttG. After a time, the rights reverted back to the author of the original work (Douglas Adams). Same for the Shogun adaptation.