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Another popular competitor to Intel's 8080 8-bit processor, Mostek's 6502 (above) and its variants had and have many fans. Found at the heart of the Apple II, the Commodore 64 and the BBC Micro, the 6502 was simple, efficient and massively cheaper — $25, instead of $179 — than the opposition.
However, it never got the advantage of a common software base across different manufacturers, and the people behind it never got enough cash to compete properly. There was a 16-bit successor — the 65C816 — that did well at the heart of Nintendo's SNES games console, and once again there are embedded variants that continue to sell.
The spiritual successor to the 6502 is the ARM architecture, which was consciously designed around the same ethos of simple efficiency, and which is alone in the world as a serious Intel competitor.
Photo credit: Dirk Oppelt/Wikimedia Commons