The first Amiga computer was released in 1985. This would later be referred to as the Commodore-Amiga 1000 or A1000 for short, the number being added when the product range was expanded. A500 (low-end) and A2000 (high-end) followed in 1987. The A500 was the most popular Amiga computer at that time; today the most popular Amiga is the A1200. The last Amigas to be made were the A1200 and the A4000.
For its time, the Amiga had some of the most impressive sound and graphics (through several coprocessors) available for the home user. Indeed, it was also used for commercial entertainment production till the mid 1990s (Video editing, 3D graphics rendering etc). NewTek marketed a special graphics rendering solution of the Amiga, called the Video Toaster - Video Toaster was used to render the space ships in the first season of Babylon 5, and were involved in numerous other major movie productions without ever being credited. NewTek also created the Lightwave 3D rendering program on the Amiga, which they eventually ported to the PC and is still being sold today. 
The operating system, AmigaOS, was also quite sophisticated, combining an elegant GUI like that of the Apple Macintosh with some of the flexibility of UNIX while retaining a simplicity that made maintenance rather easy.
The Amiga community contributed a lot to a computer subculture known as the Demo Scene. The Demo Scene was more or less a phenomenon inherited from Commodore C64 times.
The original Amiga was designed by Jay Miner. His machine was many years ahead of its time when it appeared, having features such as IRQ sharing, memory mapped IO, AutoConfig (today known as "plug-and-play"), and preemptive multitasking. Some of these features had been used previously in mainframe computers, but had never been used in a personal computer before.
Amiga models include:
Prototypes that were never released include:
Unfortunately, although the Amiga was successful in Europe, especially Germany, it was a total flop in the all-important US market, with less than a million sold. Mass-market Amigas were considerably cheaper than PCs or Macs - this boosted sales in the more price-conscious European markets, but led to Commodore being viewed in the United States as a producer of cheap and nasty 'game machines' - this image was not helped by the fact that most retail outlets were toy stores, and by Commodore's marketing campaigns which were woefully mismatched with the status-conscious American public.
As a home computer, compatibility with ordinary household television sets was prioritized over professional grade graphics and memory management. Even "amenities" such as a hard drive (on a 500) or a device for ensuring a non-interlaced display (a 'flicker fixer') had to be bought from third party vendors. While it was the only multitasking platform in the consumer marketplace for several years, robustness left something to be desired (mainly due to the absence of Protected memory, resulting in frequent "Guru Meditation" errors).
The history of Amiga owners is a colorful one, including two bankruptcies (Commodore International, ESCOM), two buyouts (Commodore buying Amiga, Inc. 1984, Gateway 2000 buying the Amiga IP from the ESCOM estate in 1997) and the licensing of the Amiga IP by Amiga, Inc., a new company founded by a former Gateway marketing employee in 2000.
The Amiga had a strong user community.
The current owner of the trademark, Amiga, Inc., is licensing the production of an updated AmigaOS ported to PowerPC, to the Belgian-German company Hyperion Entertainment. It also licenses an AmigaOne trademark to companies interested in selling hardware to users of this OS.
Numerous religious wars surround the technology implemented in the Amiga. Many Amiga users are of the belief that that the Amiga will rise again, to reclaim its glory and cast the naysayers into the abyss of anonmity. See Amiga Religion.
The Amiga keyboard, is quite similar to today's Windows keyboards, but having a left and right "Amiga" key (bearing the "A" of the (former) Amiga logo in black on the left and outlined on the right). It also has a dedicated "Help" key. It doesn't have keys like "Insert" or "Print", though. It also only has 10 function keys, instead of the 12 common to IBM PC keyboards.
The Amiga Three-finger salute, or interrupt key combination, is Ctrl + Left Amiga + Right Amiga.