Amiga graphics cards
The Commodore Amiga is used to be different from a PC and Mac since it could easily be connected to a TV. It used to be that it cost a lot to connect a PC or a Mac to a television, often it was more economic to find a solution with an Amiga than getting expensive equipment converting VGA to a signal compatible with a television.
A PC today can easily be connected to a television, most graphics card have the possibility to show output on a TV, sometimes with no drivers needed. So the Amiga is not so unique anymore.
A graphics card used to be quite expensive for an Amiga and where exclusive to expensive big-box Amiga computers since they connected to the internal Zorro slot. While the TV-out signal of the Amiga was great for games or video editing it was not so good for everyday work. A resolution of 640×256 (every pixel is taller on the height than on the width) is and was quite low, higher resolutions demanded expensive monitors and often limited to 8 or 16 colors to keep the speed of the system high. Thanks to Amiga specific graphics card it was possible to run the operating system of the Amiga in the same resolutions as the PC used.
Zorro graphics card are compatible with the A2000, A3000(T), A4000(T) and various Zorro busboards. There are two different versions of Zorro slots, Zorro 2 and Zorro 3 where Zorro 3 is the faster one. You will only find Zorro 2 slots on the A2000 and various Zorro busboards. All Zorro 2 boards are compatible with Zorro 3 based Amigas.
Some of the best graphics cards on the Amiga are:
Picasso IV by Village Tronic
The Picasso IV is the ultimate Zorro based graphics card. It has a built in scandoubler and flickerfixer so that the TV-out signal from the Amiga is converted to a signal possible to be viewed on a standard PC monitor. Picasso IV is also a very fast and stable board with expansion possibilities for sound card and TV-card. The card is compatible with booth Zorro 2 and Zorro 3 based Amigas and supports resolutions up to 1600×1200.
Picasso II by Village Tronic
The Picasso II is a stable Zorro 2 graphics card that is much slower than the rest of the listed cards here. Picasso II is a great card if you do not mind running Workbench in lower resolution with 16-bit color mode or in higher resolution with 256 or less colors.
CV64 by Phase 5
The CyberVision 64 is a fast Zorro 3 only card. It is actually faster than the CV64-3D that came after it and many consider it to be a great card. CV64 has a pass through for a scandoubler/flickerfixer.
CV64-3D by Phase 5
The CyberVision 64 3D is a Zorro 2 and Zorro 3 based card that has the option of running a small optional scandoubler card. The optional scandoubler is very rare today and not easy to find. CyberVision 64 3D was supposed to be a card that brought hardware supported 3D to the Amiga but not many applications where made that used the 3D part of the card.