My fiance and and I take Carlson Fish Oil. I'm currently taking 4 teaspoons of that a day--WITH MEALS. We take the liquid variety because we really do a high dose of it. If you are eating a standard american diet (lots of carbs, beans, processed foods, corn-fed beef (as opposed to grass fed beef), and not enough seafood) you need to get LOTS of Omega 3s to balance out your Omega 6s. Omega 6s are PRO inflammatory and Omega 3s are ANTI inflammatory and the ratio of the two are very important in your body. The only natural foods that have good amounts of Omega 3s are grass fed meats, some seafood and organic/pasture raised eggs.
Flax is NOT a good alternative, as your body has to do a lot of work to get the DHA/EPA out of a plant-based Omega 3.
If you are interested in getting a good dosing recommendation to really get the benefits of Omega 3 (which is going to be lots more than a pill a day), check out this fish oil calculator:
http://whole9life.com/fish-oil/
If you go with a pill form as opposed to liquid, I recommend the store-brand at Costco. Keep the pills or liquid in the fridge. The reason I do liquid is because I got sick of taking those giant horse pills all the time and the liquid actually tastes good.