If you like sour cream, you ought to consider making it yourself. The stuff you buy in the store comes as-is. If you make it yourself, you get a fresher product and total control over how thick it turns out.
Gabrielle Taylor, writing for WonderHowTo, explains how easy it is to whip up the stuff and how your choice of ingredients controls the end result:
To make sour cream, you just need buttermilk and heavy cream or half and half. Heavy cream will result in a thicker sour cream, so choose based on the texture you're looking for. Add 2 to 3 tablespoons of buttermilk per cup of heavy cream or half and half and let it sit at room temperature for 1 to 2 days. Don't worry about the cream going bad -- the acid in the buttermilk protects against bacteria. It should last about a week in the fridge.
Making your own sour cream requires a little patience, but it's clearly very simple. For more creamy foods you can make yourself, check out the full post over at WonderHowTo.