I think my favourite gaming era was 1990-1996, when the concept of "next gen" systems was first experimented with. People really don't appreciate it now because there isn't any equivalent, but this was a really revolutionary time when all kinds of companies were experimenting in creating next-gen systems, and branching out in a wide variety of ways.
First you had the Turbographics-16 and Sega Genesis introducing 16-bit gaming, which was huge. Especially the Genesis launched with all these amazing arcade games like Altered Beast and Golden Axe! Then the SNES came out and was even more powerful! Then you had the Turbo-Duo CD-ROM which had full-motion video and animation and CD-quality sound. Wow! The SegaCD came out soon after and was way ahead of the Turbo-Duo, and you had FMV games which seem cheesy now but were hugely impressive at the time, and then Nintendo said it too was developing a CD-rom add-on for the SNES (which ultimately never came out). You could even play CDs on them! Younger people don't realize the significance of that because in 1992 a lot if not most people didn't yet have CD players (much like PS2 DVDs and PS3 BDs). Meanwhile the Gameboy had just come out, so for the first time you could play advanced games without a TV, and the Lynx and Game Gear had 8-bit colour handhelds that you could even watch TV on (!). And on top of all that, SNK gave you a home arcade with the Neo Geo, at an astronomical price tag. No one you knew owned it at the time, but just seeing the screenshots, literally an arcade board in a console shell, it was just mindblowing. I can't stress how amazing all of this was to gamers who were literally playing Atari and NES only three years earlier. Things just all of a sudden began to move so fast. Meanwhile, Street Fighter II was re-writing all the rules of arcade games, and Mortal Kombat was re-defining acceptable content in games, it was probably the biggest that the arcade era ever got.
And before we could even wrap our heads around all of that, in 1992 we started hearing rumblings about 32-bit systems. Nintendo announced "Project Reality," which was later revealed to be a 64-bit system called the Ultra 64, and Atari was announcing it's 64-bit Jaguar. Holy shit, 64-bits?? Virtual reality was all the rage back then, and you had all these virtual reality headsets coming out. Nintendo tried this with the Virtual Boy, but like all the rest it never took off. Finally, you had Panasonic releasing the first 32-bit system in 1993, which actually was quite good. The Jaguar didn't go anywhere, and neither did the Phillips CD-i, which was more of a multi-media system and not a gaming console anyway, but by 1993 Sega and Sony were both saying they were developing 32-bit systems too (plus something called the Neptune, which turned out to be the infamous 32X add-on). To have 3D games was seen as almost reality-like, it was another example of an entire medium of gaming that hadn't existed only a couple years earlier. And at the arcade you had Virtua Racer and Virtua Fighter coming out, which blew everyone away.
So in this period of about 5 years, you had so many systems, so many different technologies and so many new things. Most of them never really went anywhere, it was mainly Genesis versus SNES, but in the background you had all these other wars going on. And then finally out of the aftermath of all this, Sony's system, which few really believed in because it wasn't Ninetendo or Sega, plus other electronics companies Phillips and Panasonic had systems of only marginal success, rose up to become the dominant platform, with the Nintendo 64 soon being released and becoming it's main competition. So out of all this convoluted mulit-platform era, by the late 1999s it was Nintendo versus Sony, and Sega was about to be bankrupt.
Microsoft entered the fray a bit later, and for an entire decade it has now just been those three companies. But think about that: for people in the early 1980s, and in the early-mid 1990s, the idea of only three consoles existing--not just having three dominating companies, because that's not unusual, but literally you only have three console systems and two of them are very similar and have almost the same games (PS2-3/XBox1-360)--that's a huge change from that earlier 1990s period. It was such an exciting and experimental time, where we started seeing things and having types of games that only a couple years earlier never even existed. For guys like me who bought every issue of Gamepro from 1990 to 1998 and followed all this stuff, it is hard to explain to people who are only really familiar with games from 1999 and on.