These are some really insightful responses. Thanks for taking the time to answer. A few lines from all of you have made me want to elaborate a little bit as to what I mean.
I don't mean more important as in "who do you love more," as no one could or should be expected to answer a question like that. I'm asking more in a "given a non major choice, which side usually gets priority?" It's the little time tallies that most people don't think about.
In my mind, the perfect example of what I'm talking about comes from a movie I had to sit though, the first Sex and the City movie (ah, the things we do for love). The red haired woman has a nuclear family, and it seems to be going all right. Her husband one night sets up a romantic dinner for the evening, which she shows up to late because one of her children's activities went too long. He shrugs it off, and they eat the cold dinner. After he's starting up the foreplay and whatnot, but she brushes him off saying "I have to take <kid> to his soccer practice tomorrow morning, I have to get to sleep now." Husband then makes note this has happened every week for weeks, and he's tired of playing second fiddle.
Now, I know it's just a movie, and situations that overblown rarely happen, but it does make me wonder how based in reality that is. Given the choice of a surprise late lunch with the spouse, or making sure the kids are driven to soccer practice, I can't say in confidence I know anyone that would take the first choice. They'll want to, but they won't do it. It seems to me that 9/10 times when there's a conflict, the kids win out. I dated a girl with 2 young kids for a while (part of my no kids decision now) and I was always left holding the short end of the stick. Routinely canceling our dates, showing up at minimum an hour late to most things, etc. I don't know I could put up with that again, especially if the kids state was after a long no kids stage.