Um... crunches or maybe try yoga. Some yoga poses really help you burn calories. Oh!!! Or try inchworms!!! you keep your feet in one spot then move your hands as far out as you can (best f you can get yourself to end up in a push up position) Then do a push up, and then walk you feet up to your hands and finally walk your hands out again and repeat the process!! Hope this helps!!
Well you want to know about the exercises that burn fat very quickly. Actually there are many ways for burning fat quickly. But you have to choose the correct one that is feasible and suitable for you.
If we arrange the exercises from high calorie burn to low calorie burn type then we will see running>swimming>uphill walking>rowing> cycling>jogging> walking. Apart from these you may also try tennis training, quickie yoga, gymnastics stretch & crunch, jumping, dancing, boxing, knee dancing etc. But my suggestion is whatever you choose try to maintain some things like be intense with your fat burning exercise, exercise larger muscles for greater calorie burn, develop a sustainable exercise, keep moving to burn fat which means don't just sit here & there, wiggle your toes, shake a leg, get up regularly and move your body! That's it.
Besides these exercise if you want you may choose some sort of weight losing program too. For this, I would like to suggest you to go through http://healthfulreviews.com/ and find the best review.