IMHO ... as a serious collector of the Classic US Silver Commemorative ...
My top-5 favorites are (in no particular order):
Oregon Trail Half Dollar ... mentioned above ... a classic created by the classic couple Laura and James Fraser.
Texas Half Dollar ... impossible to squeeze more interest into one reverse than Pompeo Coppini managed to do ... then enjoy the eagle and star on the obverse. Hard to believe today this coin was subjected to official grief as being a hodgepodge of design details.
Hawaiian Half Dollar ... just truly enjoy the native chief on the reverse ... the funky type setting on a USA coin ... and the 10,000 total minted made this from day 1 of issue a rarity and all-time favorite.
Hudson Half Dollar ... the all time greatest funky coin (IMHO) ever to be coined by the US Mint ... study the reverse of this coin and check out the moon Chester Beach placed at the 9:00 position ... the ship shown on the reverse is Henry Hudson
Half Moon as known exploring what is now known as the Hudson Bay. Great fun indeed for Chester showing a quarter moon as a symbol for the
Half Moon.

BTW ... Gotta love as well the obverse which has Neptune seated backward on a whale while a mermaid blows a song through a conch shell.
Just imagine that obverse/reverse design being approved today.
Lafayette Dollar ... Minted in 1899 but dated 1900. Many USA firsts for this coin ... first legal tender coin to depict a USA president (Washington on the obverse) ... obviously the first commemorative dollar ... the only USA coin to have it's denomination expressed as a name
Lafayette Dollar ... first legal tender coin to show the same person on both obverse and reverse ... and a lovely chunk of classic silver to collect!
Sorry .... I morphed you post into David's most popular.

Anyways ... those are my thoughts ... and I could just keep on going with the classics!
David