OK, someone's got to step up to the plate here and provide some serious quality. There's a lot of staples that are popular for a reason and need to be put forward.
I will bear this responsibility.
I actually have a "Love" playlist on my iPhone.
Here it is:
Days Go By - Duncan Sheik (my personal favorite love song - EVER EVER EVER. good hell, i can't listen to this and not cry. shut up.)
https://www.youtube.com/watch?v=ukosf7QTbuQ
Crash My Party - Luke Bryan (this is a drop everything kind of thing... not many country songs can really affect me, but this song does. cool video too - that's his wife at the end. incidentally, this was one helluva concert. my first country concert. amazing performer.)
https://www.youtube.com/watch?v=1WEpLzsdEeY
Anggun - Snow of the Sahara (holy scheit, i would totally wreck this chick if i ever had the chance - one of the most beautiful songs i've ever heard by an amazingly beautiful woman)
https://www.youtube.com/watch?v=IKdS42K_UDY
I Burn For You - Sting (just listen to the lyrics, you'll understand why this is here)
https://www.youtube.com/watch?v=u1FOLcGo9Ns
Wild Horses - The Sundays (my favorite version, hate the Stones version)
https://www.youtube.com/watch?v=BiyCkSOF1pc
We've Only Just Begun - The Carpenters (the consummate beginning-of-marriage love song. if you don't like the carpenters, screw you. SCREW YOU.)
https://www.youtube.com/watch?v=__VQX2Xn7tI
Runaway - The Corrs (huge favorite of mine this song staggered me the first time i heard it - but then again i'm a huge sucker for harmony)
https://www.youtube.com/watch?v=0fMUYU8DC1U
If - Bread (dude. come on. one of the ultimate love songs of all time.)
https://www.youtube.com/watch?v=5a_4fBH_7dk
You Fill Up My Senses - John Denver (it's john denver. john denver, man.)
https://www.youtube.com/watch?v=C21G2OkHEYo
Baby I'm A Want You - Bread (all of bread's songs could go here. but this song is amazing.)
https://www.youtube.com/watch?v=Iq3biClGRNk
The Power Of Love - Frankie Goes To Hollywood (how is it that more people have not heard this song??? amazing love song)
https://www.youtube.com/watch?v=LdnAbtIF3YM
Alibi - Duncan Sheik (don't know why i like it, but i do)
https://www.youtube.com/watch?v=VUZq8a_7X8U
I'm With You - Avril Lavigne (ya, she's weird, but this is a beautiful song)
https://www.youtube.com/watch?v=dGR65RWwzg8
Everything I Do, I Do It For You - Bryan Adams (ok, i really liked robin hood.)
https://www.youtube.com/watch?v=ZGoWtY_h4xo
Longer Than - Dan Fogelberg (if this song doesn't pluck your heart strings you're heartless.)
https://www.youtube.com/watch?v=5Go6I2_PpBU
Breathe - Faith Hill (come on. any explanation necessary? really? look at her. goodness gracious me.)
https://www.youtube.com/watch?v=yCmsZUN4r_s
Waiting For A Girl Like You - Foreigner (have you ever really listened to the lyrics of this song? amazing songwriting.)
https://www.youtube.com/watch?v=Wln6NX0V4AQ
What Are You Doing New Years Eve - Harry Connick Jr. (for the crooner fans)
https://www.youtube.com/watch?v=BNiC4xKtzfU
We Are In Love - Harry Connick Jr. (who says love songs all have to be slow ones?)
https://www.youtube.com/watch?v=zSKtsNYmeYg
She Belongs To Me - Harry Connick Jr. (connick is awesome.)
https://www.youtube.com/watch?v=R3h43az37-g
Recipe For Love - Harry Connick Jr. (ok, really awesome.)
https://www.youtube.com/watch?v=XM4mBonEcIA
Your Body Is A Wonderland - John Mayer (ya, he's a douche. but it's a great song.)
https://www.youtube.com/watch?v=N5EnGwXV_Pg
So She Dances - Josh Groban (if your girl is a dancer - hey a lot of girls are - this is a pretty cool song.)
https://www.youtube.com/watch?v=EIzA3Plv4ig
Open Arms - Journey (well... duh.)
https://www.youtube.com/watch?v=2lLmYLw0WRI
I Need You - LeAnn Rimes (well...it's an awesome song. i know it's technically a religious song, but if you listen to it as a love song, it's awesome.)
https://www.youtube.com/watch?v=S2g3j8NcCy0
Endless Love - Lionel Richie and Diana Ross (the first love song i ever fell in love with.)
https://www.youtube.com/watch?v=MP7m5VqQ6f8
Forever Isn't Long Enough - Michael Bolton (As a song goes, it's awesome.)
https://www.youtube.com/watch?v=Nq2ktTFrA6A
I Said I Loved You But I Lied - Michael Bolton (if you can get past the fabio wannabe look, this song is quite beautiful.)
https://www.youtube.com/watch?v=bv5vMJKBAbo
Suddenly - Olivia Newton John (in some ways this song cracks me up, and then i just listen to it, and it stops being funny.)
https://www.youtube.com/watch?v=eWYnLCQvBOQ
In Your Eyes - Peter Gabriel (when feeling tormented and appreciating your girl... this is a powerful song.)
https://www.youtube.com/watch?v=B3kFPBtc9BE
Can't Fight This Feeling - REO Speedwagon (what an incredibly beautiful love song. and kinda fun video too.)
https://www.youtube.com/watch?v=u9De1UXREr0
Somebody - Depeche Mode (huge love song in the 80's... danced with many a girl at many a "stomp" in those days to this song...)
https://www.youtube.com/watch?v=LgooMi4NYhY
Blow Wind Blow - Alison Moyet (i grew up in the 80's, and this was a great slow dance song back then)
https://www.youtube.com/watch?v=gzmkGLhg25A
Eden - Sarah Brightman (off the beaten path, but beautiful in and of itself - not sure if it should be classified as a love song though, but feels romantic to me)
https://www.youtube.com/watch?v=lEn0a66SrKg