I have a "Slim line case" with a flex ATX form factor motherboard, and I want a moderate graphics card. Something close to a GTS 450. A Radeon HD 5450 works but i would prefer more power. But It needs to fit in my case, so a more compact size. Length doesn't really matter but it can't take up 2 spaces in the back of the PC. I'm just using it for light gaming. It must have a VGA port and a DVI/VGA/displayport because I am using dual monitors. (Both with VGA but I have adapters for DVI and displayport.) It should be able to run all aspects of Windows 10.
It's a toss up between a Radeon RX-460 and a Geforce GTX-750 for me:
Here are a few specific UPCs:
Radeon RX-460: 778656073524
Geforce GTX-750: 843368027933
The RX-460 has DVI and DisplayPort, and there are single-slot models available.
The GTX-750 has both DVI and DisplayPort, and there are single-slot models available.