There is none. But, it's depend on the person who can exploits, dominates and make it profitable. "Weight loss" is a good one, but if you don't know how to monetize it, its useless.
In addition to what everyone else has said here: -Amazon best sellers list -Twitter hashtag search/trends -Google Keywords Research -Google+ research (look for communities discussions) -Youtube Videos (research channels and largest numbers of subscribers) -Reddit hot topics The most profitable niches of 2015 (and beyond) are related to healthcare (weight-loss, anti-aging), beauty, gambling, fitness, cyber security, dating, business coaching, self improvement, real estate, sales training, lead generation. To exploit a niche, you need to be knowledgeable and market yourself properly. Niche sectors are pretty hard to tap into unless you know the audience pain points. It's even better if you are the target audience. What's best depends on your own expertise and ability to market yourself. The least popular niche becomes a goldmine in the right hands.
am a webdeveloper and a designer also i studied 3d maya software .. can i make more money with this niche?