deb http://packages.siduction.org/extra experimental main contrib non-free
I have no problems with nvidia drivers from experimental (yet) so people want stable use the way towo says
First, do a dist-upgrade, then
apt-get install linux-image-4.0.0-towo.1-siduction-amd64 linux-headers-4.0.0-towo.1-siduction-amd64
Reboot, then
apt-get install -t experimental nvidia-driver nvidia-settings libgl1-nvidia-glx-i386
If NOT running multi-arch, you don't need libgl1-nvidia-glx-i386
The results will give you
piper@x1:~$ inxi -F
System: Host: x1 Kernel: 4.0.0-towo.1-siduction-amd64 x86_64 (64 bit) Desktop: KDE 4.14.3
Distro: siduction 14.1.0 Indian Summer - kde - (201412241440)
Machine: Mobo: Gigabyte model: GA-970A-UD3 v: x.x Bios: Award v: F7 date: 10/22/2012
CPU: Hexa core AMD FX-6300 Six-Core (-MCP-) cache: 12288 KB
clock speeds: max: 3500 MHz 1: 1400 MHz 2: 1400 MHz 3: 1400 MHz 4: 1400 MHz 5: 1400 MHz 6: 1400 MHz
Graphics: Card: NVIDIA GF106 [GeForce GTS 450]
Display Server: X.Org 1.16.4 driver: nvidia Resolution: 1920x1080@59.94hz
GLX Renderer: GeForce GTS 450/PCIe/SSE2 GLX Version: 4.5.0 NVIDIA 349.16
Audio: Card-1 NVIDIA GF106 High Definition Audio Controller driver: snd_hda_intel
Card-2 Advanced Micro Devices [AMD/ATI] SBx00 Azalia (Intel HDA) driver: snd_hda_intel
Sound: Advanced Linux Sound Architecture v: k4.0.0-towo.1-siduction-amd64
Network: Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller driver: r8169
IF: eth0 state: up speed: 1000 Mbps duplex: full mac: 90:2b:34:a5:99:2d
Drives: HDD Total Size: 8001.6GB (22.0% used) ID-1: /dev/sda model: Hitachi_HDS72202 size: 2000.4GB
ID-2: /dev/sdb model: ST3000DM001 size: 3000.6GB ID-3: /dev/sdc model: ST3000DM001 size: 3000.6GB
Partition: ID-1: / size: 199G used: 124G (66%) fs: ext4 dev: /dev/sda3
ID-2: swap-1 size: 4.29GB used: 0.16GB (4%) fs: swap dev: /dev/sda1
Sensors: System Temperatures: cpu: 15.1C mobo: N/A gpu: 36C
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 239 Uptime: 12:01 Memory: 1680.2/7971.6MB Client: Shell (bash) inxi: 2.2.18
No issues, glitches, artifacts, etc, playing Skyrim
YMMV
For vbox, all I did was
apt-get install -t experimental virtualbox virtualbox-dkms virtualbox-source virtualbox-qt virtualbox-guest-additions-iso