Suggestions on a new yoga mat?

It is time to purchase a new yoga mat. The one that is being retired was a $14 mat I got on sale at a fitness store. It served it's purpose for about 5 years or so.

I am looking for a good mat that isn't going to break the bank and one that I won't slip on (the one I have now, I slip in downward dog within minutes.

any suggestions?
are the ones at Target/Walmart good?