Real talk? You're asking the wrong question. You should be asking, "Are you happy with the state of your marriage?" No marriage is exclusively happy times. But through the struggles of the relationship, people can be happy with the state of their marriage.
Personally, I answered, "More positive than negative." I'm not always happy with the state of my marriage. There are many times when I'm not happy with myself, and that hurts my relationship. There are many times when I feel my wife and I aren't communicating properly, or aren't handling a situation correctly. My marriage is mostly happy because we work through these things. But we can be dealing with a cr@ppy situation, nothing happy about it, and still be happy with our relationship in how we're handling it.