Outside of the scientific and evolutionary bits, I find it wonderful to allow myself to be vulnerable enough to admit the importance of another person to me, to long for him/her, and also to know that I am self sufficient enough to be my own person. It's just nicer when I don't have to do everything alone. I've always been more of an individuated person, and found it wonderful to learn how to have full attachments with others, including admission that life is better, more rich, and wonderful when it's shared.
I like this ... a lot.
Honestly I'd say that yes, for me it is a need. I need other people in my life to be fulfilled and happy. I need affection - both emotional and physical. Will I survive without it? Sure. Will I be happy? No. I don't have a problem saying I need other people.