m68k.
The 68000, 68010, 68020, 68030, 68040, and 68060 chips and derivatives. Also, the 683xx, a scaled-down version which additional embedded peripherals was popular in many embedded systems.
This CPU family occupies an interesting place in computing history. It has been used everywhere from regular computers (AppleMacintosh, AmigaComputer, AtariSt) to high-end workstations (Sun, SGI, TI, Sony, NeXt, Omron, Apollo, and the list goes on), to low end devices (TI-89 and better calculators, Sega Genesis, Atari Jaguar, PalmPilot).
The TektronixElevenKayScope (which used SmalltalkLanguage) also had a 68k processor in it, as did/does numerous other test instruments from Tek and others.
Plus, it was just plain fun to program in AssemblyLanguage.
Fun indeed... and quite jarring to go from 68k assembly to x86 assembly! -- KyleCordes
Isn't the DragonBall? processor a still "living" member of the family?
DragonBall? processors (early versions) have 68k-compatible instruction sets, but RISC cores. Newer versions of DragonBall? have ARM cores. The 683xx series (the embedded versions of the 68k series) are still around. The ColdFire? series, also from Motorola, still has 68k-compatible instruction sets.