Living alone would be very comfortable for me, personally. I like to play games online with friends and chat, but I really don't actively go out to pursue activities with friends. Being alone with either my music, games, books, etc is comfortable with me. The only exception is my girlfriend, who I'd enjoy spending time with in pretty much any amount. Ironically she lives far away right now, but plans on coming back in the future.
If I didn't have a girlfriend I'd not have a feeling of love pulling me towards someone, so I'd most likely be as content as I am most days, although lesser than now. It really depends on how much you need someone to love, and need someone to love you. A singular person, not friends or family.