Honestly, my favorite thing in a story is a character (main or not!) who has really close relationships with their friends and/or family! That's not to say that I won't enjoy a series without that element; I just really like it when it happens. It's kind of why I'm drawn to series like Kingdom Hearts, Final Fantasy XIII, and Tales of Graces (just to name a few that come off the top of my head)—those games pretty much revolve around friendship and near-familial bonds, and it's just always so heartwarming to see the characters in such relationships interact with each other. Basically I like cute and happy things.