What are the best softwares are available for rendering?

In terms of quality class probably KeyShot - looking renderings posted here.
I work in Vue 9 Esprit - competitive price and it can squeeze out a lot.

Autodesk 3D Max absolutely the best.
There is almost no difference between real photo and the finished rendering.

I think, the best renderig software - that You know how to fully exploit :)

solidworks and photoworks

I agree with Salvatore - the best is 3D MAX.
Now I use KeyShot - and I'm very happy :D

Solidworks , Creo Elements Pro , Keyshot

keyshot

You have many options of software available as people have listed here:
SolidWorks PhotoView 360
KeyShot
Creo Elements Pro
Autodesk 3D Max
Vue 9 Esprit

And others not mentioned:

Bunkspeed Shot
Blender
Maya
even Photoshop

The issue is as Tomas pointed out "that you know how to fully exploit". Many of these softwares have a steep learning curve and can take weeks before you are able to produce anything up to the standard you want.
Therefore the "best software" should be one that's simple to pickup and use with a small learning curve that can produce meaningful results.

I would suggest taking a look at SolidWorks Photoview 360, or Keyshot.

I definitely agree with Matthew, pro rendering is a job in itself, sometimes even more time consuming than the conception itself.
As a long time solidworks user (for architecture!) I decided to use modo from luxology to render (photoview 360 engine). I am getting decent renders after six months of quite hard work, the mindset is different, as are the objectives.
Another factor is computation power, rendering a 500 part assy in a photo-realistic setting with daylight and shadows will shake up a CPU, and correcting a small mistake will take hours of rendering.
So ... it all depends on what you need, Beautiful work has been done in Sketchup (see their site) and much crump has been done with more reputed software.
Good luck

Luxology's Modo - We use it for the ability of the add-on kits availble and the cost of hte software is much easier on your wallet than some listed above.

Я работаю в Solid PhotoView 360. Но мне не нравится. Визуализация получается не такой реалистичной как хотелось бы.