Crochet (knitting) yarn, which type is best?

I just started crocheting last month. So far I have made a purse and some hats. At first I used Red Heart, Medium(4), it was a little bulky and not soft enough. Than I tried I Love This Yarn(from Hobby Lobby) same weight, both are acrylic, both this brand was softer and not as bulky. What kind of yarn do you use, and for which projects? Where do you buy the yarn (favorite internet site, store)? Cheapest? Which kind of yarn is best for an afghan stitch dishcloth?