He told me in the beginning, but I've forgotten
However my observations say:
1. Communication and quality time
2. Words of affirmation
For me:
1. Acts of service
2. Communication
We make time for a little getaway whenever we see each other (long-distance). He usually plans the whole thing, which I love. I really hope that he never ends up not enjoying doing the planning because I think it's fantastic. Me, I try to keep our communication off of depressing topics, not because I don't think they should be discussed, but I don't want to get into the habit of seeing my partner as a sounding board for negative stuff. Vice versa.
So, I reel myself and him, nicely, if we start going into the deep end.
When we talk, we wholeheartedly focus on each other (for the most part). He's bigger on frequent conversation than I am, and sometimes that feels like a lot of pressure for me. Yet even when feeling pressured, by the time I'm finished with the conversation, I feel so much better and happier (see above).
One of my favorite things is to go to work at his office
I'll sit in the conference room or his office while he's running around having meetings etc. Then occasionally, he'll come in, make sure there's no one within view of the windows and give me a kiss. I love that