For the CUDA 4.2 based apps the minimum recommended drivers are,
310.90 for Windows
304.88 for Linux
Note that some more recent GPU's require a more recent driver just to work.
The GK110 GPU's (Titan/780...) only work with CUDA 5.5 app versions. The following drivers are required to run the CUDA5.5 apps (also work for GT104 cards trying to run CUDA 5.5 apps):