If you are creating something with very high-polycount (>millions) or complicated 3d scenes (heavy dynamic simulation), and you want real-time performance, then you might consider buying a workstation card (eg. Nvidia Quadro series, price range from RM 1k to RM 6k).

Otherwise normal gaming card (Nvidia Geforce series) will do.

Nvidia is better choice for 3D application as it has greater Open GL supports.