VMware Workstation blew my mind when I saw it demoed in (I think) mid-2000 [1]. I genuinely couldn't believe what I was seeing - it seemed that revolutionary, running an OS inside an OS on a desktop. I wonder whether VMware's problem nowadays is that, having basically invented the technology, they've become almost synonymous with the category of virtualisation tech - kind of like "Hoover" for home appliances - and their other products get less attention.
(I know that VMware didn't invent the idea of virtual machines. But my perception is that at that time, virtualised OSs were mostly found in mainframes.)