Our household CD collection has generally tended towards the jazz/folk/rock/alt country genres. But with a third member of the household also musically inclined, there's a new category- children/family/kids.
A great blog of kid's music, Zooglobble, is now over in my blogroll. I recommend you visit it, as well as the Land of Nod web store. Our son loves the Land of Nod collections.
We've also been on a massive Elizabeth Mitchell kick lately. All of her albums are stellar.