I'm talking about a general field. Just as with most people, a D minor chord triggers a sad emotion, and C major triggers a happy one, are there chords that triggers romantic feelings in general?
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.
Chords don't work that way. Imagine asking which notes are sad or romantic or whatever. That clearly doesn't make sense because it's not a note that gives a feeling, it's the combination of the notes, how and when they are played, what instruments they are played on, etc.
The same thing is true with chords. Even a chord progression is not a large enough structure to be tied to one specific emotion. You have to get close to a complete musical phrase with whatever melody and harmony and articulation before most listeners will feel something related to that phrase.
Don't think of it as what chords. Because the only difference between a major chord and another major chord is one just sounds higher or lower in pitch than the other. But they're the same intervals so they sound the same.
The difference between minor and major though is significant as you mentioned minor does sound sadder than major. But if we compare one minor chord to another minor chord as mentioned before it's just a difference in pitch as the intervals are the same.
Emotions are mainly triggered by sets of chords and the overall key of the song rather than one specific chord. If I were you I wouldn't focus so much on chords, rather scales/keys.
But romance can be either thought of as happy or sad. If you're talking about a breakup definitely minor key (Greensleeves is an example). but if it's the start of a new relationship and has more optimism then go for a major key (see Love me Tender by Elvis)
The most romantic song I can think of is Romance d'amour. I think it captures well the sadness that people associate with romance and hence its in a minor key.
note: that said, there are plenty of romantic love songs written in major keys (ask Elvis and the Beatles). so it's more of a subjective thing. To me I just get moved more by minor keys. They definitely sound sadder and more mysterious to me.
But to directly answer your question music is just made up of major (happy) and minor (sad). It's how you combine these to create other emotions.
To answer your question, I took the time to examine the top love songs of all time (from popular American radio anyway).
The key and therefore most significant chord of each of the top 20 (and this is subjective, I know) are:
Endless Love by Lionel Ritchie and Diana Ross – A
The Greatest Love Of All by Whitney Houston – A
My Love by Paul McCartney and Wings – Bb7+
When A Man Loves A Woman by Percy Sledge – C
Silly Love Songs by Paul McCartney and Wings - C
Unchained Melody by The Righteous Brothers – C
I Want To Know What Love Is by Foreigner – Dm
Crazy Little Thing Called Love by Queen – D
I Can’t Stop Loving You by Ray Charles – D
Love Me Tender by Elvis Presley – D
Whole Lotta Love by Led Zeppelin – D
I Love You Just The Way You Are by Billy Joel – D
(Your Love Lifted Me) Higher and Higher by Jackie Wilson – D
How Deep Is Your Love by The Bee Gees – Eb
Your Song by Elton John – Eb
Love Me Do by The Beatles – G
You Make Loving Fun by Fleetwood Mac – G
I Will Always Love You by Whitney Houston – G
Why Do Fools Fall In Love by Frankie Lyman and the Teenagers – G
So, the short answer is 'D'.
'G' comes a close second.
And apparently 'F' isn't a romantic chord at all.