What is your favorite type of social interaction?

Last night I had this five hour long conversation about everything and anything. It was very profound and exactly the sort of conversation me and this friend usually have, but I found myself feeling differently than I usually do. Generally, this sort of thing leaves me feeling energized and happy about truly connecting with someone. This time I just felt tired. I had been enjoying the conversation, but I was happy for it to be over, as well. Has anyone else felt like this?

One on one conversations with people who have similar interests to mine are my favorite sort of social interaction. What is yours?

Who do you most enjoy being around? Does it change with your mood?