It isnt a bang for buck card :P Kind a depends on what you want. If you want the most power available on a single GPU, than the titan is your card. Altho imo it is a bit wasted on just one 1080p screen. Altho, you didnt say what screen set up you are running. Im just assuming its 1080p
If you just want to play games on max settings on a 1080p screen, with some exceptions such as crysis 3. A 670/7970 is enough for that.
It is up to you. You cant go wrong with a titan, but the same is true for a 680 to a lesser extent.