I have been using Octane Render for over two years now and it has proven to be an amazing tool. It is a render that is unbiased (uses real algorithms to simulate realism), and fast. It uses GPU to render almost in real time. It is probably the cheapest renderer out there that is still ranked among the best renderers such as Vray or Maxwell. I recommend anyone who does renderings of any level to give it a try. It is very easy to learn and is worth the little effort you need to get started.
Take a look at this review by Evermotion: