Just to be extra confusing, while NVIDIA and AMD develop the hardware and reference models the cards are usually manufactured by third parties. These third parties often tweak or enhance the cards in some way and the same reference model may come in multiple variations of memory, clock speed, ports and other features. More expensive editions of the same model are occasionally overclocked and have additional performance, so it's worth checking out before making a decision.
This is a list of all of the manufacturers we currently have stock recorded for. You can use this table to select a particular favourite manufacturer if you don't want to shop around for others. Clicking on a manufacturer below will take you to a filtered list showing graphics cards only made and sold by that manufacturer.