There are a few issues at hand here. Mg per mg, EPA/DHA from krill oil is better and more bioactive. The problem is that There is krill oil supplement that gives you enough to get you to a high dose 3gr of pure EPA/DHA daily. Source Naturals and Neptune Gold Krill oil which are two of the best krill oils out there only have about 300mg of EPA/DHA per two capsules. Who the hell is going to take 20 of those capsules daily. It would get very expensive. As far as the best fish oil Nordic Naturals is one of the best companies in the world. They are actually a pharmaceutical company in Norway and their source of fish comes from non-farm fish from the cold waters. Their methodology on how they extract, store and purify the fish oil is on a whole different level. Their Ultimate Omega DHA/EPA content is not far behind pharm grade Omega 3.
More important than just the amount and looking at a number of DHA/EPA is the source of the omega 3. From people that are expert in this field, we have been told that there are a few things to look out for:
1) Buy the most expensive fish oil-there is no free lunch. Think about it, if i told you we can go to a restaurant and have a 12oz prime filet mignon for $3.99 would you believe it? Hell no. High quality EPA/DHA content comes from only a few companies around the world that have the know how to make sure they dont go bad.
2) This related to the last point, but if the capsules come in a clear bottle, automatically is a warning sign to stay away. If the company had any fucking clue to begin with, they would not put the fish oil in a clear bottle. UV rays will destroy omega 3. Many 3rd party tests are done regularly and some show that not only many fish oil never even meet what the label claims, but sometimes more than 50% of the oil has gone rancid.
3) Fish oil that is extracted form lets say cold waters naturally vs fish oil extracted from farm raised fish have a completely different bioactive level. Of course one will be more expensive than the other but it is what it is.
So what to do? I myself, take 2 capsules of the Neptune Gold Krill oil twice a day (breakfast and dinner). And then take anywhere between 3-5 capsules of the Nordic Natural Ultimage Omega along with the Krill oil. This gives me a nice little combination of both krill and high quality Omega 3. When i combine this with my good fats such as daily avocado, 3oz good nuts and 10mg crestor daily has given me an amazing lipid profile.