Many songs are suitable, I recommend 10:

Stay here forever (Jewel's)

Craigie Hill (Cara Dillon's)

I will always love you (Whitney Houston classic)

Without You (Mariah Carey classic)

You`re Beautiful (James Blunt)

when you say nothing at all (Ronan Keating)

just the way you are ( Bruno Mars)

kiss me (Sixpence None The Richer)

stay with me (Sam Smith)

the power of love (Celina Dion Classic)

If there is anything else you need, feel free to ask