I like a lot of different types of music so you might find some you like and some that you'll just go "what the...?" at but hope that you like at least some of these!

Evanescence - My Immortal
Evanescence - Bring me to life
Breaking Benjamin - I will not Bow
Breaking Benjamin - Evil Angel
Within Temptation - what have you done now (rock version is better in my opinion)
Within Temptation - Forgiven
Within Temptation - ice queen
Celtic Woman - Caladonia
Celtic Woman - You Raise me Up
Celtic Woman - Danny Boy
Katie Perry - Teenage Dream (I think that's the name, haven't lstened to it in a while)
Uverworld - D-Technolife
Nightmare - The World
Glee Cast (seriously) - Keep Holding On
Mariah Carey - Hero
Jyongri - Lullaby for you (I love both versions)

If I think of some more I'll post um but for now that's it! Hope that this helps!