I know this is a very old thread, but Nvidia just released their newest card that unveils the new Maxwell architecture. It is the GTX 750 (and ti). for around $150, you get 2GB of GDDR5 Ram in a card that is only as long as the length it takes to get from the PCI e x16 3.0 slot to the back of your computer, It also has a power consumption of 65W, which means no extra cords (for older computers) most 300W PSU's can even handle this card no problem.
There are different models but I recommend The EVGA one. here is the Link