I've seen a lot of nice coins from members on here, but I'm not ashamed to admit that this one is among those that I covet the most. That leathery/chocolate patina gets me every time.
Agrippa. (Died 12 BC). Æ As. (28mm, 10.46g). Rome mint.
Struck under Gaius (Caligula), (AD 37-41).
O: Head left, wearing rostral crown.
R: Neptune standing left, holding small dolphin and trident.
RIC I 58 (Gaius)