I realize this may be a bit of an unpopular opinion, but honestly, I feel like the 2nd generation of gaming, epitomized by the Atari 2600, has aged better than the subsequent generation typified by the NES.
The second gen was limited enough that the games were extremely simple, but that also meant there was less leeway to fuck them up. With the additional complexity of the NES however, came a flood of games that are pretty much unplayable these days thanks to cheap and sloppy game design.
Obviously the NES also brought with it great games like Mario Bros, and the 2600 also had its share of broken shovelware, but by and large, I feel like nowadays the average 2600 game is more fun and playable than the average NES game simply by virtue of being more elegantly simple.
For me it's similar to how the 4th gen (SNES/Megadive) has aged better than the subsequent N64/PS1/Saturn gen. In both cases, I feel we went from simple but more polished games to more complex but as a result messier games.