For me personally, I'm loyal to Honda. None of the Hondas I've driven have ever given me any trouble and have lasted for a long time. My main considerations are fuel economy, reliability and it's Consumer Report rating. I'd also consider Mazda, Subaru and perhaps the new Ford Fiesta.
For a family of four (two children), I'd recommend either a mid-sized car or a mini-minivan, like the Mazda5 or the Kia Rondo. These are four cylinder gas savers, but they have the capacity to haul up to six or seven passengers in a pinch.