The Game Boy by Nintendo was one of the first handheld systems I owned. For me, it was technology ahead of its time. Never mind it was in black and white (or shades of green), I could play video games so long as I had batteries. I wasn't allowed to bring my Nintendo on family vacations, but this was portable enough that I could.
It breaks my heart that kids today don't realize how much technology has advanced and that something like this didn't really exist before.