I'd like to hold a 1915 S $50 Octagonal gold coin. The shape and reverse owl intrigue me?
But realistically, every U.S.A. coin is commemorative. Each commemorate events, presidents, military leaders, places, ships, trees, monuments, ideals, animals, anniversaries, etc.
This said, I really like 1922 Grant Memorial Halves. (Obverse star or not).
Also, the 2001D American Buffalo silver dollar.
Great post. More will chime in.
Peace ✌