What are rare US 2 dollar bills?

No US $2 bills printed since 1953 are rare; while they only make up about 1% of all bills in circulation that's still hundreds of millions of bills over the last 60 years. To find any of value you'd have to go back to dates that are effectively impossible to find in circulation. These include, among others:

1928-B : $70 to $1000

1918 : $175 to $1000

1896 or earlier : $175 to $4500 depending on date