Not to be overly contrarian, but the fact so much discussion is placed purely on visual feedback seems to disregard much of what is technically impressive in games to begin with.
You can look at a game like halo 4, and we can compare it to reach, I would say that neither are technically superior as many of the graphic upgrades come at the cost of other meaningful changes. How often have you backtracked through a level in halo 4? Not much because many of the doors lock on you. How often have you been able to save the location of a sniper-rifle or power weapon in halo 4, and been able to return to it? Not often, this is because the number of assets in the scene is much more limited (just blow up a covie tower and see how many gibs are made and how long they sit around for), and while the base geometry, lighting and other aspects have been improved, it's done so at the cost of scale and gameplay. The maps are more linear, offer less freedom and exploration, are much smaller and so forth. So is it really technically superior? Is there anything superior about diminishing gameplay in favor of graphics in a medium which is defined by gameplay and not visuals?
Perhaps its best to look at other technically impressive accomplishments in games. I think a game like gta5 does an amazing job at offering up a consistent online component in a world with extraordinary scale. A game like minecraft struggles to load chunks of the world for 1-2 players, and rockstar has managed to develop an online infrastructure that allows for several people to all share within one global massive game-space with nearly as many hiccups (and it looks very good to boot). Forza is another game that stands out for me in that it offers an immense amount of physics calculations on the spot, no it doesn't look as good as gran turismo in a realism litmus test but that's besides the point (imo). Another game would be halo 3, not because of of graphics again, but because of its novel lighting method, producing actual dynamic range lighting by rendering 2 separate frame buffers with different lighting configurations then combining it to produce some of the best results, period. Even more impressive is that in split screen co-op, each view gets its own render output running at their own framerate giving you the best results for any home competitive setting. Maybe even something like shadow run which attempted to combine pc and console gamers. Trying to develop drivers and support for pc and console protocols from different devices and configuration of devices on a sinngle pvp system would also be an incredibly tricky feat, not to mention trying to balance the entire game out etc.
if anything, visuals are some of the lesser impressive feats of games. You can make some really amazing looking games with simple tricks and art.