For almost anything the average consumer would want to do, a gaming PC is the best of the best. However, if you are going to be working with CGI and video compositing, then it would be better to have a OpenGL-accelerated graphics card rather than the DirectX-accelerated graphics card used in gaming. Of course, because all modern PC games use the DirectX API, this means that a system with an OpenGL card would be crap for gaming. That isn't to say that a DirectX card wouldn't work with compositing and CGI applications, the previews will just be slower and with some compositing packages the rendering times will be as well. Image software such as Photoshop, on the other hand, relies almost exclusively on the CPU so it wouldn't matter which type of graphics card you went with.