Almost all of the fish oil you can buy actually comes from 1 company and have been tested for mercury (by ConsumerLab.com and Consumer Reports):

http://www.usatoday.com/news/health/2004-12-15-fish-oil-usat...

None of the major brands had significant amounts of mercury.

I'd just get the cheapest kind, given that it's likely from the same company.

This was already posted, but it bears repeating (so sayeth me): that one company is singlehandedly destroying an entire ecosystem on the Atlantic seaboard: http://www.nytimes.com/2009/12/16/opinion/16greenberg.html

I don't care what the benefits are, there is no excuse for such behavior in this day and age.

My fish oil is Costco brand and it says it contains anchovy, bonito, and sardines. It also says it's made from wild deep sea fish. I think I've also tried liquid cod liver oil and supposedly these were cheaper than the pills. In fact I haven't even seen a brand of fish oil with menhaden.

If you haven't already, check and make sure it's not also full of hydrogenated oils as filler. I once saw such a fish oil supplement at Costco advertised as "full of heart healthy omega 3s."

The Costco (Kirkland) brand that I have lists Fish Oil Concentrate, Gelatin, Glycerin, Glycerol, d-Sorbitol, and Natural Tocopherols as ingredients.

These are the Costco store brand.

FYI: For a very expensive, but pristine fish oil (actually from green lipped mussels in New Zealand): http://moxxor.com/

(I'm an investor)

I know the Moxxor guys - Noel Turner is an incredible entrepreneur story - recently started taking the product how have you found it vs. fish oil?

Indeed. I didn't notice much change myself, but I already get a healthful portion of omega3s and antioxidants from my food. My parents had reduced joint pain/inflammation.

"Business Opportunity through MLM Home Based Company"

Wow, kudos there for managing to instantly lose my trust just reading the title of the page ..

Here is a list of the companies that are at least self-reported to meet various safety standards:

http://www.edf.org/page.cfm?tagID=16536

Walnuts and flax seed are another source of omega3.

True, but it's not in the form that is easily digested by the body.