Never made a list before, but I'd have to put honesty right at the top.
A sense of humor has to be balanced with intelligence though. Hard to make one a priority over the other so they tie for second place.
Gonna go out on a limb on the last one, but somebody that is a good sparring partner. I know that sounds weird, but my husband and I do not always agree on the issues, but our arguments are awesome! No vitriol, no oneupsmanship, just plain ole good debate. Neither of us never win, of course, but that's the beauty of living with somebody else. It keeps things very interesting. It also helps if he knows he's an asshole, too.