Fights where taking kicks on the arm results in some breakage! Some organizations (mostly kickboxing like K-1) recognize a kick on the arms as a "blocked" kick. In traditional Muay Thai, this is not so. If the kick lands hard and effectively on the arms, it still scores.
Here are some fights where arms get broken from kicks!
Jomhod vs Bayram Colak: http://youtu.be/rexNv-tk0kQ
Sakmongkol vs Perry Ubeda : http://youtu.be/TBVbppMcHXY
This is a GREAT fight. Sak dislocates his shoulder in the middle of the fight, but then keeps pressing forward and eventually breaks Perry' arm in the 5th.
Kru Clifton vs Frederic Rosenberg: