Intel HD Graphics (onboard GPU) Drivers: These drivers are updated every couple of weeks, which quickly made the Boot Camp 4.0's drivers (dated early 2011) obsolete.
NVIDIA GeForce (discrete) Graphics Drivers: It's likely that the official NVIDIA drivers won't work on your NVIDIA-based Macs (though it's worth a try), so you will likely have to resort to a bit of driver modification to get the latest drivers to work. It sounds worse than it actually is. Simply head over to the LaptopVideo2Go forums and choose the latest GeForce driver series category, such as:
These forums host literally all Nvidia drivers that are released through various channels (e.g., OEMs, developers, etc.). If you're getting any of these, watch out for the "MS WHQL Certificate" tag and read the forum comments carefully to avoid potentially buggy drivers. First, you need to clck on "Download Driver", download the package and extract it. Then, right-click on "INF Modified" and save the INF file under the "Display.Driver" directory found inside your driver folder:
That's it! This will remove all hardware checks and will allow you to install NVIDIA drivers on your Mac.
Broadcom Wi-Fi Drivers: The broadcom chip is present in most recent MacBooks, iMacs and Mac Minis. Station-Drivers.com has the latest drivers. Scroll down to the "Broadcom Wireless 802.11a/b/g/n controller" section and get the latest drivers for your OS.