@sozobe,
Funny - I was thinking and thinking - and what pops into my head that damn Barney song - I love you, you love me....I know my younger daughter loves Taylor Swift (which was mentioned), my other daughter loves Sugarland - "Stuck Like Glue" is a fun love song.
I also thought of Katie Perry - but they wouldn't be appropriate. I can think of some that my kids like - like some of Katie Perry but I sure wouldn't recommend them.