Suburban. It seats 7 total. We have 4 children to cart around plus sports equipment among other things so it works for us. Once our two older children move out we will be buying something a bit smaller. Right now we need the space.
How old are your kids? I have a Ford Taurus and can easily fit the neighbor kid's carseat in back with my 2 kid's carseats.... for little ones a 4 door sedan would work. I imagine when they are teens you will need a SUV or a mini van so everyone has room. That middle seat makes older kids unhappy.
I'm dreading the day when I have to drive something giant. I get 32 mpg right now!