Go to newegg.com (navigate through the following
* Computer Hardware
* Video Cards & Video Devices
* Desktop Graphics / Video Cards
Power-search (set the following)
* MAX: 75
* Check DirectX 10, 10.1 and 11
* Check HDCP Ready
Click Search...
Sort by Best Rating.
It currently looks like a GeForce 9500 or ATI HD 4650 may be your best bets. If you can find an nVidia GeForce 8800 around your price range, that will be a far better card. It's worth noting that CUDA (nVidia cards only) is better supported in software currently.
If you can spring for a little more, an nVidia 8800, 9800 or 260 series card would give you much better results than the above options. A 9800 series probably the best option under $150.