The Altair is pretty widely regarded as the first 'real' home computer. It's perfectly poised on that dividing line between "hobby electronics" and "consumer product".
I've never seen one in person though unlike Apple IIs, TRS-80s, TI-99/4As, etc.
I have to admit I've never seen those in person either. I have played with Amstrads, Amigas and Commodore 64s, though, and I have a BBC Micro in a box under my desk. :)