What is the most effective weight loss supplement on the market today?

I would AVOID any weight loss supplement. They are not healthy. I lost weight (lots of it) without a supplement. How? Read on: Cut all processed food and watch the weight fly off! Eat veggies, fruit, unprocessed meat, low fat dairy. Stay AWAY from white sugar, flour, corn syrup. If you can’t hunt it or gather it, don’t eat it! I lost 30 lbs eating this way. You would be amazed how much better you feel once you cut out sugar,white flour, and the chemical additives in processed foods! You will have much more energy. Substitute your sugar intake with Stevia (300X sweeter than sugar) and no calories or carbs! It is natural and does not raise the glycemic index. Important tip: Shop only on the outer rim of the Supermarket. Good LUCK!!

it aint carb cutting an bread-lowering, cuz those are essential. cut the fat out alot,eat well balenced(not like me lol)

This is often disputed by medical professionals because many of these diet supplements contain dangerous components in them. This is especially true since the FDA does not pre-approve dietary supplements, but they are regulated as foods and not drugs.
Anyway, I guess the best way to answer your question is that you have to find something that works well for you. Different people will swear by different things. Good luck.