If you want really great tasting yogurt, the kind you can eat plain out of the carton, look for Balkans style or natural yogurt.  Check the ingredients.  The best yogurt only has milk products (this may include powdered milk or whey protein) and bacterial cultures.  It is naturally thick and creamy, and very, very delicious.  No gelatin, no aspartame, no high fructose corn syrup, no stabilizers, no pectin, no carageenan, no corn starch, no unpronounceable chemicals.  It’s best to flavor it yourself, if you want it for desert or breakfast.  A spoon of sugar or honey, or some jam, or cut up juicy fruit like oranges or strawberries.  It’s also good with a bit of sugar or honey and cinnamon or other spices.  I also love it with a couple spoons of undiluted juice concentrate.  That makes it into a kind of instant smoothie, no blender required.

The best supermarket brands in Canada would be Astro and Olympic.  These aren’t any more expensive than Yoplait, and they’re wonderful. I have never seen those brands in the States, but I think Breyer makes an all-natural yogurt.
Just look at the label.