(oh, god, no...please not Céline Dion...)
I'm going to say Count On Me by Default - it's a gorgeous song and, to me, it's totally their relationship at the beginning, with Lois always running back to Clark for comfort and he's always there for her.
Anytime you need someone
Somebody strong to lean on
Well you can count on me
To hold you till the healing is done
And every time you fall apart
Well you can hide here in my arms
And you can count on me
To hold you till that feeling is gone
