I'm using an Nvida 550ti and it works perfectly for both BD and BD-3D playback. Since you mention 3D, it's important to note that you really do need to get a GPU that supports not only BD, but BD 3D offloading if you want to play back 3D movies. The two are separate- and if your GPU doesn't support BD 3D offloading, the burden is put on your CPU which usually will cause stuttering and heat problems unless you have an awesome CPU. I also game with it (World of Warcraft).
For several years I upgraded back and forth between ATI and Nvidia - but I just kept having problems with patch after patch on ATI. . I love the 550ti and will never go back to ATI. You should be able to get a 550ti for $120-150 price range, I got mine on sale from Newegg for $119.