What is the highest value V nickel?

The highest value by far is for a 1913 Liberty nickel. Only 5 of these are known to exist, and recent sales have been in excess of $7 million.

However, 1913 Liberty nickels weren't officially authorized coins. It's not clear exactly how they came to be, but the best speculation is that some Mint employees struck them clandestinely using dies that had been prepared in case the new Buffalo design wasn't ready in time.

Among official Liberty nickels, the winning date is 1885. Please see the Related Question for more information.