Trust really. Having someone that trusts me and who I can trust in return. Having someone that listens to me and takes my advice or who can offer it to me. Someone who can turn to me in a crisis and be there for me during mine. Someone who I can share experiences with and create fresh memories. Someone I can have fun with and share in the absurdity of the world. Someone with whom we can enjoy one anothers bodies, through either sex or simple physical comfort like a kiss, cuddle or a hug.
Something like that. I don't expect someone to encompass all that I want, but some would be nice.