Connection on a deep level
Then great love making, because we know each other deeply.

I have to chuckle a bit. You specifically said "just your #1 thing" and very few answers have just one thing. We humans are stubborn.

I think having a lot in common is one of the most important things for a good relationship. I like to have someone I can talk to about things and have them at least give a crap about what I care about. A lot of money isn't important, but after my marriage and supporting a husband for quite a few years, just having a job of his own is a must-have.

Someone who will give me space. At this point in my life I'm totally self-sufficient and don't need someone else. I could handle a relationship with someone like me. I wouldn't mind being wanted but don't want to be needed.

Honesty

Connection. Not necessary chemistry, but that feeling that you could talk to this person for hours about anything, where nothing feels forced or rushed.

That elusive middle ground where they don't want to just put another notch on their bedpost and move on, but they're also not choosing bridesmaids' dresses after exchanging three texts.

Seriously, though. It's mostly about finding the right balance between freedom and commitment, for me. I don't want to be in anyone's pocket (ever again.) I don't particularly want to cohabit (that might change as I get older.) But I do crave that special connection with one human being, where we're both more important to each other than just about anything else in the world. Someone who texts or phones every day, and who I see most weekends, would be ideal.

Just somebody who honestly loves me

Compatibility, getting along.... Too simplistic?

Someone who gets me and laughs with me. if you could spend a minute in my head and not go insane we would be a perfect match.

Someone who "gets" me and vice-versa.

Well, there are actually three things for me, I want laughter, friendship, and romance.

Thunderbolts!

Mental strength and a kind heart.

Honesty. I’m an irrational person and tend to let little things bother me so if those little things actually mean something, I’d like to know. Yes, I have trust issues so you’d need to cater to everything about me before I even consider letting you into the rest of my life. I would of course return the favor, but I would feel better about doing that if I knew what I was catering to.

I was surprised when I found someone I could trust, and liked that feeling more than being in love.

My answer is in the question: a partner. Not just a friend, not just a lover, not just a paycheck. A partner. Someone to lean on, cheer for, help out, play with, cuddle, laugh with, talk to, fuck, share responsibility with, and all that jazz. The only hitch is that they must be present to win.

Intellect

Tacos.

Common interests, similar sense of humor, and compassion for others.

Friendship is the foundation...

Intelligence in a woman is the most important thing to me.

Honesty. Nothing can be made better and everything can be made worse without being honest with each other.

Kindness. To me, to others, to himself, to animals, to the planet.

Loyalty