A niche with high CPC rate are considered best niches according to me.
High CPC rate sites.
1.Beauty products/tips or make up products/tips niche has high CPC rate. If you visit a beauty website, you can able to see high revenue ads like Maybelline, Nivea,etc. These are beauty companies and always occupy their place in TV ads. They pay super good like 2 dollars for one click. That's super high.
2.Review sites just pay superb high. If you visit a particular niche's review sites,then you can see.For eg. If a website has reviews of smartphone, their ads will be just super high. Reviews are gaining ground for me.
3.Smartphone or computer niche websites pay high because they all are rich companies and the pay is $2.That's ultimately good
There are still many high CPC rate niche but you need to think what ads will they show if i create a website in this niche. How the ads are rich? How they pay?