Diskettes The computer I had loaded programs off tapes, and that was a pretty "involved" process taking anywhere from 5-20 minutes. Then we got an Atari 800XL with a disk drive, and not only did loading only take a little while, but you could also save to the disk without special workarounds.

Flat panel displays The first computer LCD screens were small, not very impressive display quality wise, but they were SO THIN! They were making an image without the large back of a "traditional monitor". I'd vowed to own one one day. (turns out that CRT screens still beat them in some areas to this day...)

Home broadband before about 2000, i had to sneak around a long telephone extension cord to be able to get online for at most a couple of hours. Then one day we got a message that they were rolling out this "broadband cable" thing, and my whole world just shifted. My machine was ALWAYS ONLINE. The internet was ALWAYS THERE. I could download things that used to take me minutes in just seconds. It blows my mind even today still.

MP3/XVID/DIVX Suddenly my harddrive could fit whole songs and later whole movies...that coupled with the whole broadband thing opened up a whole new world of possibilities.

SSD It'd used to be normal for a computer to take a couple of minutes to start up. Even when it was, doing more than a couple of intensive drive bandwith things could really bog it down to the point of being unusable. Then SSD's came along. They started as pretty small things (still have my 30gb OCZ drive somewhere), but they were so incredibly fast. Systems now started in seconds. Games in a fraction of the time. And everything just felt snappy all the time.

It feels incredible to live through these times, where we take for granted that everything will always get better/smaller/faster during our lifetimes (hell, every year even) where that has never been the case at any point in history.
And technology wise it'll never get any worse than it is right now. That's pretty goddamn neat.