Potting Soil

What are the most popular brands of potting soil?

so for my science project, im doing an experiment on how potting soil affect a plants growth. name some popular brands, n ill give the best answer to the person who comes up with the most. plz give brands that arent too expensive cuz i dont wanna run my bill up too high. thanks!
i need four different brands plz.

Schultz makes potting soil as does Miracle-Gro. Schultz is a little cheaper than Miracle-Gro, which is why I have a bag of it at my house. Just go to the different home centers in your area. They will all have 2 or 3 different brands.

http://www.schultz.com/ProductCategories/Soilsamendments/PottingSoilPlus/

http://www.miraclegro.com/index.cfm/event/ProductGuide.product/documentId/9bc1eea5ad5baedbf4e90353fa98608f

Coco Coir Premium Potting Soil