Billy Joel

Try emusic. Don't join, use their search feature.

"Best" is a matter of individual taste and appreciation.

I'd go with this one:

Billy Joel - River of dreams - (Amazon)

I know this BJ Thomas song is not exactly what you requested (not Billy Joel) but it's one of the sweetest prettiest lullabies that combine R&R and harmony. It is what I thought of immediately when I saw your post. It has the Beach Boys-like background singing (some debate about whether it's them or not) in the background. Nothing sounds better. BJ Thomas - his best ever.

Thanks guys.
Billy Joel is kind of flavour of the week in our house, because of an excellent documentary which has just shown on TV, about his first trip to Russia, sorry, the USSR.

I like his River of Dreams album.

http://www.amazon.com/River-Dreams-Billy-Joel/dp/B0012GMWF2/ref=sr_1_1?s=music&ie=UTF8&qid=1403468564&sr=1-1&keywords=billy+joel+river+of+dreams


This is a great video from his "in his own words" concert where he talks about the song and then sings it.

http://www.dailymotion.com/video/x50ujs_lullabye-billy-joel_music

Lyrics

Goodnight my angel, time to close your eyes
And save these questions for another day
I think I know what you've been asking me
I think you know what I've been trying to say
I promised I would never leave you
Then you should always know
Wherever you may go, no matter where you are
I never will be far away

Goodnight my angel, now it's time to sleep
And still so many things I want to say
Remember all the songs you sang for me
When we went sailing on an emerald bay
And like a boat out on the ocean
I'm rocking you to sleep
The water's dark and deep, inside this ancient heart
You'll always be a part of me

Goodnight my angel, now it's time to dream
And dream how wonderful your life will be
Someday your child may cry, and if you sing this lullaby
Then in your heart there will always be a part of me
Someday we'll all be gone
But lullabies go on and on
They never die
That's how you and I will be