The three ear-bones that connect the eardrum to the cochlea are the three smallest bones to be found in the human body. In order after the eardrum, they are:

• the hammer - incus
  
• the anvil - malleus
  
• the stirrup - stapes

These are also the three bones (six I guess if you count both sides) in the body you are least likely to break.

They do get dislocated and/or infected though ...

While all three bones are responsible for transmitting sound from the eardrum to the cochlea, the stapes is the one that attaches directly to the oval window. Normally, the three bones act to amplify sound going into the cochlea but the muscles tensor tympani and the stapedius muscle can act to diminish movement of these bones, helping to protect the ears from very loud sounds.