Compassion is a great one, a trait I feel like we don't spend enough time talking about as an element of success. I've worked with many extremely talented, genuinely bright people whose business skills suffered because of a lack of compassion and empathy: for their users, coworkers, or people they generally (and probably correctly) considered less intelligent than themselves. Making a conscious and genuine effort to understand someone else's position and needs will get you MUCH further than dogmatic self-righteousness - even if you really are right. ;)
