What's the correct driver to use with a GeForce 6150SE nforce 430 on Ubuntu and Ubuntu flavours?

I found that the correct driver (working well now for two days) is the nvidia-304 which can be installed from repositories. This might be problematic if you are making a clean install because the Geforce 6150SE will not work well when installing from the Ubuntu DVD: the Ubuntu live session will freeze, so follow this sequence:

1. Boot from the DVD and press Space to choose different methods of installation.
2. Choose Experienced Install.
3. Install Ubuntu.
4. After install is done, press CTRL+ALT+F1 and login.

5. Update your system:

   sudo apt-get update

   sudo apt-get upgrade

6. Install the driver:

   sudo apt-get install nvidia-304

7. DO NOT run nvidia-xconfig (THIS IS IMPORTANT).

8. Reboot the system (just press CTRL+ALT+DEL)
9. Login normally.
10. Open Nvidia X server settings from the dash.
11. Backup your configuration (you can copy and paste it to a txt file)

I hope this helps others, it's worked for me (so far).

Correct can mean lots of things.

The nvidia drivers are proprietary and do not integrate well with the rest of the free software ecosystem and community. The nouveau driver is the preferred one, but in Debian testing and unstable it has a bug with the 6150SE, which you can workaround by inserting into /etc/modprobe.d/local-video.conf:

options nouveau noaccel=1