Frankly, I'm a bit torn as to which I think was "better".
More revolutionary? The first 3D gen, of course. So many new gameplay ideas and analogue control becoming a standard (and rumble) but like people have said, it didn't age particularly well. Ironically, I probably hold more 2D games on the Playstation (and definitely Saturn) in high regards than 3D games, with the Resident Evil series, Tekken games and racing titles being among the exceptions. Polygonal games on the N64 fare better and I will say that, considering the technical limitations, Nintendo produced some really fun and engaging designs with things like Mario 64, Wave Race and Zelda.
But the HD generation complimented the rise of high definition TVs quite nicely and huge, sprawling interconnected worlds were very welcomed. Getting to play PC games like Elder Scrolls at that level on console was fantastic. There were a lot of generic shooters and dull colors though for sure and I definitely agree with @Kyuu that going from so many 60fps titles during the 6th gen to the stuttering 30s was very disheartening (although the frame rates of 5th gen games were even worse) but we still got some pretty smooth playing stuff like Modern Warfare at least (before COD had worn out its welcome). And I must say, something like Bioshock just wouldn't have had the impact it did on me if it had been delivered on lesser hardware at standard definition, not to mention the Uncharted series or The Last of Us.
Personally, I very much enjoyed both of these generations. In fact, I'm likely in the minority here but I much preferred the industry in general during both of these eras than Gen 8. The PS4 was pretty good, but Xbox One, WiiU, 3DS and Vita all contributed to a generation I don't look back on too fondly. In any case, I voted for Gen 5 simply because of the gameplay advancements but it's still close for me.







