For me humor is a very important trait for all the people I interact with. I don't like being serious and I'm very childlike but I hate it when the other person, specially I see this on guys, is goofy all the time and just doesn't know when to stop. I don't like "absurd" or stupid humor, I'm more of a black/sarcastic humor person. But yes, humorous guys are (8) atracttive as long as they're not plain stupid (then it just drops to 1) xD
Other thing, just like
>>10 said, the ability to really talk about something seriously and discuss it politely. Keeping an open mind, I can't stand people who think they're always right and get all bitchy about it.