Nicknames I Like: MLB

Iron Horse

Big Hurt 

Charlie Hustle

Penguin

Blade

  

Splendid Splinter

Say Hey Kid

Nails

Toy Cannon

Cobra

Mr. October

Sultan of Swat

Louisiana Lightning

Blue Moon

El Presidente

Sweet Music

Big Unit

Spaceman

Mad Hungarian

Wild Thing

-  Not a definitive list, obviously.   

-  Williams had the nickname before Major League came out.

-  Photos from TCDB.

-  I have all these cards, with two exceptions.  Feel free to guess the two for bragging rights.