The hardest song for me to hear without crying is "Believe" by Brooks and Dunn. It always makes me bawl. My husband is not an empath, and it even makes him cry.
One of the songs (along with it's vid) that made me cry a lot (and still does) is Whiskey Lullaby by Brad Paisley and Alison Kraus... I do not smoke, drink, never had similar happenings in my life or cheated, and yet, everytime I hear it my heart breakes. But I still think it is a beautiful song.
Another one that I cry at is Take me away by Globus. The message really resonates with me I guess xD
For some reason The Islander by Nightwish also had similar effects. I didn't even know english too well when I first heard it (in fact, when I first heard all of them), but the rythm and the fact that I caught the main idea (I always pay attention to the music and just reaaally little atrention to the lyrics) were enough. Well, I guess clear hints are always more than enough for us...
Other songs that bring out stuff
like that would be Sakura Drops by Utada Hikaru, Angels by Morandi, and more songs from Linkin Park (numb, breaking the habbit...)
However, loving the fact that you put Hero in there... I also really enjoy the likes of Enrique Iglesias, Ricky Martin or Darren Hayes (and Alexander Rybak, hehe :D )