simple question,which RAW converter has the best demosaic process?

I actually have Lightroom, DXO and Photo Ninja. I agree with the Op's words about LR (whose workflow I like) and DXO (good lens softness correction and geometric distortion correction). I also agree with Pictus that Photo Ninja appears to be better than both.

I have only had it about 6 weeks and originally got it because its highlight recovery is 'far' superior to both LR and DXO (and I live in Thailand.) But the more I use it the more I like it in terms of overall detail and quality. It is well worth giving a trial although be aware that it has very limited functionality i.e. no batch processing, DAM etc...