First game what had amazing graphics, true next gen was Gears of War for XBox 360 in 2006. Played that game at start and that was strongest jump in my gaming experience! For that time game looked like movie. I know that was not that, but effect was just amazing. Next game was Uncharted. Only year later, but difference with Gears of War was big enough to be amazed again. Of course that was not so strong like with previous game but still. Next game was Uncharted 2. That game was better in graphics in all moments. Geometry level, textures, lighting, shadows, animation, all was way above first Uncharted. Nex game was Gears of War 3. Because that was very huge step for series. Difference with Gears of War 2 was even bigger than 2 compared to 1, and 2 compared to 1 also was big step forward. Also Gears of War 3 proved for me what on XBox 360 is possible make game with PS3 top tier exclusive level of graphics. There was a lot games on XBox 360 and PS3 what was also very impressive, a lot better than previous games. And more impressive was what all those games was for one console or another. So that was very interesting to observe how much more developers could get from those machines. Truly miss that times now.
Now there is imprpvements for one console, but not as near as then, and games was developed for year or two, not 3-5 years as now. I will not write list of those games from 7th gen, because list will be long.
I thing everyone know that games what aslo was impressive.
As for 8th gen, for me next amazing game after Gears of War 3 was REd Dead Redemption 2, (I still havent completed that game, probably should one day). That level of graphics and attention to details was just amzing. True next gen in all aspects.
Of course on 8th gen consoles was a lot of impressive games. Also on 9th gen consoles, but 9th gen still continues. But I also can say there is one very impressive game on 9th gen. Next after Red Dead Redemption 2. That is Senua's Saga: Hellblade II. Again, true nex gen in all aspects. But this time game really looks like movie. At least like CG movie. And was real proof to me what 9th gen consoles can render graphics what is on different level than 8th gen consoles. Before there was doubts. I still don't know how PS5 will hold against XSX, because there is difference in power between consoles. One developer said two years ago what for now games looks the same, but in some two years there will be difference, because XSX have more power. I also can add there is difference in memory bandwith.