For me, the 1990s stand out as the last decade I felt gaming was consistently improving.
Now, this could simply be a bias stemming from the fact that the 1980s and 1990s were my childhood and teenage years. It seemed to me that almost every year or two gaming had improved! This continued through the 1980s, through the 1990s and into the very early 2000s. But by 1997, this is where things began to become a bit rocky, as I'll explain.
As a near lifelong Nintendo and Sega fan, I felt this paradigm fell apart with both companies in about 1997. That year brought the sudden collapse of the 16-bit generation and a seeming lack of energy behind both the Saturn and the Nintendo 64. It was particularly apparent given the massive drought of 1997 on N64. It was the first time I felt let down by these companies. The absence of RPGs on the N64, even through imports (Japanese wasn't a barrier by this point with abundant translation guides), was particularly problematic for me.
On the other hand, the PlayStation continued the trends of the 16-bit era through the rest of the 1990s. PSX also saw massive franchises that had limited releases in earlier generations to a worldwide audience. However, I didn't have the same enthusiasm for the PlayStation 2.
In essence, I didn’t particularly enjoy Nintendo or Sony’s transition into 3D gaming. While both the Nintendo 64 and PlayStation 2 had their gems, I didn't particularly "love" many games on either console. N64 was far from SNES, and PS2 was far from PSX - again, in my experience; the PS2 was wildly popular. Nintendo's followup, the Gamecube (for me) was just PS2 with far fewer games and nothing exclusive that really hooked me outside of the original westward release of Animal Crossing - my first time playing the franchise, but one I'd been interested in since the N64 era.
But it wasn't the PSX that I felt the trend of improvement ended on. From the ashes, Sega came out with the Dreamcast, right at the end of the 1990s. The Dreamcast was everything I wanted the N64 to be... while it lasted! Skies of Arcadia was the last game I fell in love with (probably) until Super Mario Galaxy. I felt like the Dreamcast was the console I had always wanted the Nintendo 64 to be, but it was killed by rampant piracy and Sega’s being in the crackhouse as far as finances go. Again, it might have been that the PS2 era coincided with my early 20s, but this is when I really went hard on retro gaming for the first time, and newer games fell into my "these are less interesting" category. So, while it was the early 2000s, Dreamcast (for me) was really the last 1990s console.
And just for closure: I did fall in love with gaming again somewhere in 2006 between the launch of the Nintendo DS Lite and the Wii. Nintendo had been reinvigorated around this time with touch generations and motion gaming. Plus Nintendo stopped hating RPGs and RPG fans with the regime change that had occurred a few years earlier.
tl;Ii - 90s