I'll attempt to answer such things despite having been born at the tail end of the 1980s.
Super Bowl LI
Super Bowl XXXIX
Super Bowl XLII
It has to be 9/11. Considering when I was born, I don't really think anything else comes close.
Computers went from being a weird, expensive nerd hobby, to a household item for the middle-class, to a household item for everybody, to something everyone keeps in their pockets at all times. I remember my family paying close to $1,000 for a Macintosh computer when I was about seven (calendar year 1996/7), and it was the greatest thing since my cousins gave me like thirty NES games a year earlier. We didn't have internet, but boy did I have fun wasting time on that thing.
In 1998, we got a Windows computer with *internet*, and a whole new world opened up. In this amazing new world, I could learn and name of every single Simpsons episode and its production code. It was pretty incredible. I would just spend hours scrolling through those episode lists and trying to figure out which episodes I hadn't seen yet, making lists of my favorite episodes, etc. Oh, and occasionally I did non-Simpsons things too.
This is a tough one to answer, considering I was born four decades too late, but I'm curious to know whether having an abundance of information at our fingertips has taken the wonder out of things. Like, if I saw a gorgeous waterfall, it probably would have been much cooler if I hadn't already seen a bunch of photos of waterfalls and other nature-y scenes all over the internet. Or, I can imagine looking at Stonehenge in person and thinking, "Wow, my old Windows XP wallpaper sure looks nice!"
Since I've been carried, computers in general have been a pretty gigantic thing, and I'd argue that the benefits are indeed very nice. I suck at verbal communication and enunciation while speaking, so it's much easier to communicate my thoughts by typing them, so talking to people online is way simpler than it would otherwise be. Online ordering means I can buy pretty much anything I need without having to physically go out, find the thing (assuming the thing I want is even located in a nearby store -- no need to check every one for that rare CD/book/whatever!), and then transport it back to my house. I've discovered a ton of great music, TV shows, movies, books, and other media that I probably never would have known existed if the internet didn't serve as a catalog of everything that exists. My job wouldn't be possible without computers, and I love my job. I've literally met a ton of great people (I'm assuming they collectively weigh more than 2,000 pounds) thanks to the magic of the interweb. And computers are just fun to use in general, so there's that, too.
Probably GPS, just because of the complexity that's apparently needed to make it work. It's the only thing that needs both special
and the other type of Einstein relativity, or something! I don't know.
Either that or space travel, just because of how
little we've done with the technology we have. I mean, OK, we went to the moon a few times, and it turned out to be kind of a dull place, with some white rocks and some white craters and not a whole lot to do up there. I can understand not wanting to go back. But I'm kind of disappointed that humanity (read: people/agencies with the money to make it happen) seemed to lose interest in space travel in general for a few decades, and we're just now beginning to hear about companies -- like, you know, that Elon Musk one, SpaceX or whatever -- with plans to build Mars colonies.
The answer I gave two questions above probably covers this.
For a while, I've had a mental list that I call my "passive bucket list," which is a lamer version of a bucket list in which I list the things I want to
see happen during my lifetime, even though I, personally, will likely have little or no role in making them happen. My passive bucket list, as of the last time I thought about it:
1. Watch Eagles win Super Bowl2. Watch humanity establish first Mars colony
3. Witness liberation of North Korea
OK, so I didn't have very many ideas, but I feel like all of them could happen within my lifetime, if not within a decade (and maybe that's optimistic, but I prefer optimism). Heck, if the Eagles can win a Super Bowl, anything can happen.