Hello VEGASGUITARS.

Well...not so easy to answer.

All depend on what kind of 3D modelling you have to deal with.

Based on my personal experience and the experience of many professional 3D artists/engineers, in short you can consider these suggestion :
(I talk here only about NVIDIA cards, I don't have any personal experience of AMD GPUs)

I have and use everyday a custom overclocked version of the very powerful Gtx 1080 Ti and it's a beast.


1) YOU NEED TO CREATE 3D MODELS/SCENES FOR ENGINEERING AND/OR MANUFACTURING

In this case you have only ONE mandatory choice : THE EXPENSIVE QUADRO FAMILY CARD
I suggest you at least the PASCAL line, P3000 or (better) P4000

2) YOU NEED TO CREATE 3D MODELS/SCENES ONLY FOR RENDERING AND/OR 3D PRINTING

In this case you can go without doubt on the cheaper and powerful GeForce line.
I suggest you at least the Gtx 1060 which has 6GB VRAM.

3) YOU NEED TO CREATE 3D MODELS/SCENES ONLY FOR RENDERING AND/OR 3D PRINTING AND FOR (ALMOST) REALTIME GPU RENDERING AND VR

Go without doubt for the Gtx 1080 Ti!

That's all.

Ciao!