You may also wish to check out trueSpace 7.6 Which is now free, yes FREE ????!

http://www.caligari.com/default.asp

You REALLY DO have to check out this site.

This includes the lightworks renderer, and also supports a V-Ray option for  $299

This is actually a very powerful modeling and rendering solution for a free download.

I'll have to check out Pov-Ray, I first used it about ten years ago, as command line only, I guess it's come on a bit since then :)

On the subject of which is the best renderer, I think as others have said it really depends on the user and what you want it for. It's not so much the size of the engine, It's really about who's driving it ;) and whether the controls suit your style, work method, and way you think.