For use with Poser, you mean? Anything Nvidia-based (from the past two years or so) should be just fine. Nvidia has excellent driver support. As thgeisel says, Poser doesn't make use of 3D hardware acceleration, so an old Geforce2 MX is just as good as the latest Geforce FX 5900 Ultra. If you're planning on using anything else along with Poser (games, DAZ Studio, Lightwave), then I'd recommend more recent products, as good hardware acceleration will be an important factor. Nvidia's Quadro line is best suited for workstations and high-end applications like Maya.