FreeHand is probably the most high profile, if not well known nowadays, since it led to a lawsuit brought by pissed off ex-FreeHand customers (which ultimately ended in a shitty settlement).

There's also a full list of their acquisitions here, which might be fun to scroll through: https://en.wikipedia.org/wiki/List_of_acquisitions_by_Adobe

Figma is the most recent. Behance and Frame.io are some other high-profile Adobe acquisitions.

FWIW, Flash is still very widely used in the 2D animation industry, as Adobe Animate.