1.) The birth of a child - his own obviously
2.) The death of a loved one - especially a spouse or parent
3.) A woman cleaning his wounds - Have you ever seen any movie where a man gets hurt. He can have anything happen to him sword, spear, you name it but he will invariably not flinch until the woman is cleaning his wounds.
4.) Penile cancer - all you men out there. You know you were thinking it I just said it...
5.) Death - most men would rather cry than die except for Chuck Norris who is impervious to both
6.) Sappy Movies - JUST KIDDING these actually make most men laugh. The reason we laugh is because we don't understand you women. We have no other weapon in our arsenal except laughing. Don't be offended.