Here are 2 solutions :
1) you wish to use integrated Intel (not the best solution to get power and resources but you can try it), you can uninstall all nvidia drivers. End of the problem. (Once done, if Fxdrake bothers you, you can create a xorg.conf file just with "X -configure" as root, it should create a temporary file that you can try before installing it with a command that will be given by the console).
2) you wish to use your nvidia graphic card, the proprietary drivers are usually good at running them under Linux, so, keep the driver nvidia current : the package name is x11-driver-video-nvidia-current, and the dkms that goes along with it. Remove : "nouveau" and "intel".
You may have to reboot once or twice. You also may need to first create a xorg.conf for nvidia, which you can do as root in console with the command "nvidia-xconfig" which will generate one, usually best fitted for the machine where it lives.
You will also see in the menu "More Applications > Configuration > " : NVIDIA Display Settings menu entry to configure the screen. You can fine tune brightness, contrast and such in the menu X Server Color Correction. I let you discover the other menus... I don't know much about the settings in the other sections.