Anyone actually try the purity omega 3 supplements?

I've tried Nordic Naturals and some others, but the one I stick with is made by Nature Made that I get at the grocery store. When comparing labels, many of the fish sources are the same, and there's information out there that most products are safe with regard to mercury and impurities from processing. Some of the more expensive ones say that they have no fishy burp aftertaste because they have "a pleasant flavor", (read "your burp tastes like the flavoring"), thus I'm still aware of the burping. It doesn't always happen, only at times, and I've gotten used to when it does. After doing my research and experimenting, price ultimately determined my choice.