It would be hard to pick a favorite under normal circumstances, but the way things are in my life right now, I'd have to say https://www.youtube.com/watch?v=lu9ySiS7... and https://www.youtube.com/watch?v=FriW0rF7...

http://youtu.be/Do32g82qilk

http://youtu.be/uqv5b0UjR4g

I have a lot, but....
https://www.youtube.com/watch?v=k7in-9E3...

"Have I Told You Lately That I Love You" are two different songs by Elvis and Rod. The version by Elvis is the old country song, and Rod's is the newer pop song. Two different songs. Both good though.
Michelle? Really? I can think of better Beatles songs than that.

Layla by Derrick and the Dominos (Claption)
Suite Judy Blue Eyes by CSNY
If I Were a Carpenter (Robert Plant's version)
'Till the River's All Run Dry (Don Williams)

Hard to name one, I'll give you a few:
Play Me, Neil Diamond
So Far Away, Carol King
I Want to Know What Love Is, Foreigner
I'm On Fire, Bruce Springsteen
Feels So Right, Alabama
Unchained Melody, Elvis Presley
Final Touches, Conway Twitty
Plain Brown Wrapper, Gary Morris
First Time Ever I Saw Your Face, Roberta Flack
Just to name a few. I have a huge collection of music and I could easily name hundreds more.
Two more: Fur Elise and Moonlight Sonata Bethoveen

We went to see 50 Shades this weekend, the movie was not superb, but the music was really well done. Even a lot of songs and artists I don't care for, really did an excellent job on the remakes for the movie. The music was breathtaking. The books were much better than the movie, however, and I don't care what the critics say. My question to them is how much experience do they have with real life or any of the subject matter?

…can’t choose just one… here is a sample.
When a Man Loves a Woman - Percy Sledge
https://www.youtube.com/watch?v=rq2P8pTr...

Bleeding Love - Leona Lewis
https://www.youtube.com/watch?v=Vzo-EL_6...

Since I've Been Loving You- Led Zeppelin
https://www.youtube.com/watch?v=SAR7KmiC...

I Will Always Love You - Whitney Houston
https://www.youtube.com/watch?v=3JWTaaS7...

Only you (and you Alone) – The Platters
https://www.youtube.com/watch?v=Fs6Y5GCX...

Because You Loved Me - Celine Dion
https://www.youtube.com/watch?v=ih1945e4...

Let’s Get It On – Marvin Gaye
https://www.youtube.com/watch?v=3j3okb3k...

Still You Turn Me On – ELP
https://www.youtube.com/watch?v=_8VHHcd0...

"If".........I think by Bread...........(if not, corrections accepted)................".....and you and I would simply fly away."

If I were going to pick one, it would be No Place That Far, by Sara Evans.. https://www.youtube.com/watch?v=8F9LCu5P...
I've loved that song since I first heard it.

One song from our wedding...

https://www.youtube.com/watch?v=jorJh8DT...

Here is the one that brings tears to my eyes every time I hear it...like right now. Heard this when I first started dating my now husband, and we danced to it at our wedding 20 1/2 years ago.

https://m.youtube.com/watch?v=Rpq5vDccLT...

"Have I told You Lately That I Love You," Elvis or Rod Stewart.... "I've Been Loving You Too Long," Otis Redding....

Any one of many early Beatles songs would be in contention for the best love song. I'll go with "Michelle".