"best" is a relative term.
It is always recommended to use the manufacturer's driver as it may contain customizations that are needed or desired for their hardware. This is particularly the case in laptops, for example, and those with dual graphics.
So, always try the manufacturer's driver first, and then the Intel driver, as a general rule.
First and foremost, the drivers provided by the manufacturer will have been tested by the manufacturer and their operation (and interoperability) verified on the target board/system. You cannot say the same for the standard driver releases. They could introduce changes that are incompatible with the particular target board/system. A common example of this is differences in the operation of some part of the hardware as a result of how the BIOS initializes this hardware. In this case, changes in the BIOS initialization code may be required to support this standard driver.
Secondly, in some cases, the Intel standard drivers are modified by the manufacturer to support unique features of their board/system. For example, laptops supporting hybrid graphics (which combine the use of the Intel HD Graphics engine with another vendor's (NVIDIA, ATI/AMD, etc.) graphics engine) will have a modified version of the driver to support (amongst other things) switching between the two hardware engines. In this case, if you install the Intel standard driver over top of the manufacturer-provided version, this switching capability will likely not work. The same likely goes for the driver provided by the other graphics engine vendor.
Hope this helps,