Let's work from the 70s on forward:
late 70s - the VCR (Sony Betamax hit the market in 1975, JVC/Victor VHS in 1976)
early 80s - the personal cassette stereo (Sony Walkman - 1979)
mid 80s - the CD player (Phillips and Sony set a standard in 1982, and Sony sells their first CD player)
mid 80s - the home computer (Apple II in 1981)
late 80s - the home PC (IBM introduced the desktop PC in August 1982. It was never intended to be a home computer. It was the proliferation of PC "clones" in the mid 80s that brought the price down to a level where it could compete in the home market)
early 90s - cellular telephone (wireless phones existed since the 40s. Rulings by the FCC in 1987 allowed use of modern [800Mhz CDMA/TDMA] technology)
mid 90s - the Internet, or more to the point, the graphical browser (ARPANet started in 1969, Mosaic [now Netscape] browser released in 1993)
late 90s - the DVD player (standard set in 1995, first DVD-Video player sold in the US in 1997)
Some people may say that PDAs and Pocket PCs are THE technological innovation of the early 21st century, but there are still competing standards to work out, and they have not reached the level of necessity or near-necessity that you are considered a Luddite if you don't have one. This may happen in the future, but not yet.
Now we have to wonder: what will be the next world-altering consumer electronic device or technology? I'm talking about the sort of development that, in 5 years or less, will be as commonplace as the above. Not merely an improvement on an existing technology, it should be so revolutionary that there is no past point of reference, or so evolutionary that the older technology withers and dies (remember LPs and MS-DOS?).
What are some of the possibilities? Just look around. Will digital music (exists solely as an electronic file and does not have a physical format like a magnetic tape or plastic disc as it's primary source) be the way we all listen to music in 5 years? Will digital cameras cause film-based cameras to be just an outdated hobby?
I have my opinions, but I want to know yours. Let me know what you think will be the sort of thing that, ten or twenty years from now, we can look back with nostalgia and say "Remember the days before..."