G5 PowerMacs (All single-core, dual-core, single and dual-CPU models)
The introduction of the G5 in the mid-2000's was a turning point for Apple and arguably for the entire personal-computer industry, being the first 64-bit platform to be well-supported and marketed to the mainstream. It blew the doors off it's 32-bit predecessors, and at the end of it's relatively short production life had been made available as a liquid-cooled, dual-CPU, multi-core monster. They are still a viable machine today... If you are lucky enough to own one, Feel free to discuss here.