You should look for earlier-date nickels with mintmarks and key dates (e.g., 1950-D) and the very early Jeffersons. The rest of them don’t command much of a premium if any. Dimes, quarters and halves were 90% silver before 1965 so you should grab all pre-1965 dimes, quarters and halves.
What kind of nickels are worth half dollars?
Nickels: 1964-and-before (plus quarters, and silver? half dollars) EXCEPT for the War Nickels 1942-1945 with the large mintmark above Monticello (including a ‘P’ for Philly) which have silver in them and are worth well above face. You should look for earlier-date nickels with mintmarks and key dates (e.g., 1950-D) and the very early Jeffersons.
What was the content of US silver coins before 1964?
From the 18th century until 1964, US silver coins were comprised of 90% pure silver alloyed with 10% other metals in order to make the coins more durable and less prone to wear.