Omega-3's are great. However my personal opinion on any kind of "miracle cure" is twofold. 1. It is better to try to get the substance as it naturally occurs in food than to take it in a supplement, and 2. No food is so excellent for you that you can't get too much of a good thing.
1. It is more fun to eat than to take a pill, IMO. Omega-3's are in delicious stuff like fatty fish (salmon and tuna). Eating 2-3 servings of fatty fish per week will help you get your necessary Omega-3's. A sprinkling of ground flaxseed daily, in your morning smoothie will also ensure you're getting enough.
2. There are some risks with Omega-3s. Most notably: thinning of the blood (a good thing for most of us, but dangerous for those who bruise easily or already have thin blood), and stroke, among other things.
The important thing is to get them from the appropriate source for you, and to take them in an appropriate dose for your body. As to whether you get them in pill/oil form, or from food, well, that's a matter of personal preference.
A good starting point:
http://www.umm.edu/altmed/articles/omega-3-000316.htm
