@fBoyle-- I've heard that the molecularly distilled fish oil supplements don't cause fishy belching afterward. I guess the distilling process gets rid of the fishy taste. The downside to those type of fish oil supplements is that the distilling process removes the beneficial vitamins and the manufacturer has to add synthetic vitamins back in.
I personally use liquid fish oil supplements in different flavors. I don't enjoy the taste but the liquid type is the best because it's more potent and gets absorbed better by the body.