D.K.
We use plain (unflavored) yogurt. It is way cheaper if you buy the larger (32 oz) container. We used Stonyfield Farm initially because it was the only one we could find with whole fat milk. Now we do either Dannon or Stonyfield with lowfat milk (I think 2%). You should be able to find that in your supermarket. Almost all of the little 'baby/kid' yogurts are loaded with sugar (sugar if organic, HFCS if not) and the plain yogurt is not. We added chopped/pureed real fruit to it and it really doesn't need any added sugar.