James Barton Longacre
75% Copper, 25% Nickel
The 1875 Three-Cent Nickel is a relatively common date and it represents a nice, affordable example for the type. Mint State examples are relatively common, even in Gem condition. PCGS has certified 16 MS-66s (as of January 2012), but only two in MS-67, and none finer.
Keep an eye out for the interesting variety that shows the top serif of misplaced 1 sticking out from Liberty's neck (FS-301).