In order from "Holy Smoke, that's good," down to... "Mmm, pretty good."
Stellar Forge
I think the stellar forge should go down in history as one of the most outrageously ambitious procedural generation systems ever created! NMS is nice and all, but the fact that they have created, here, a system that generates an entire galaxy, approaching reality while allowing for actual NASA data to be injected on the fly is an astounding merger of gaming and science. Stellar stuff!
VR
The fact that even after an entire year since the Oculus was released, Elite dangerous is THE game to beat. I've played many other VR games from their store and nothing touches the sheer balls-to-bones implementation of VR in this game: It is baked into this game from the foundations and it shows. Moreover, the fact that this game is far more intricate than many of the other "fob" or "novelty" titles that use VR for the sake of it just shows how much foresight was put in.
This cannot be overstated and is why the "other" space games which either don't have VR or won't have it by the time they come out are seriously missing a trick.
Sound
The sound in this game has always been first rate, but the DTS update recently was the icing on the cake... p.s. Sounds make sense most with a head tracker or VR. Phenomenal 3D spaciousness.
Game Scale
A consequence of the first point, perhaps, but the fact that you could have a scale of 100 LY per meter displayed on your screen and the map would be about 1km wide and long and 100m deep is just MIND BLOWING. No other game comes close to this grand scale. The concept of supercruise is a contentious point, but I believe it gets across the idea of scale without making most daily trips odious. Engineers and Neutron Stars help, too. Grand!
Play NMS for a few minutes and it's immediate how ADS Teenager focussed their scaling system is. The fact that you can see a space station orbiting a distant planet, but you get there the space station is about the size of an outpost. not only that but you can reach a planet in 2-3 hours at surface speeds!
Local Scale
When I first started to play this game, I felt that the Eagle and Sidewinder were about the size of a station wagon. and that the trees along the landing pads of luxury stations were merely pot plants.... This changed with VR, when you suddenly realise that the cockpit of the T9 is two storeys high! Marvellous!
Graphics
The style guides for the Lakon, Core Dynamics and Gutamaya ships are outstanding. The station interiors are also sumptuous. Especially in VR. The hyperspace jump exits where the star rushes toward you are epic (although, one gets too familiar with them to notice after a while.)
The CMDR avatar is also a nice (but redundant) touch. Great stuff...
Vehicle Control an Interface
Ships are enjoyable to fly with a HOTAS and are quite navigable while using VR if your HOTAS has enough widgets. It is the only game that flawlessly recognises my X-65F Joystick analogue thumbstick, which I use for vertical and horizontal thrust.
the T9 is a monster! It feels like a monster and it flies like a cow!
SRV Wavescanner
Before the bug struck, the wavescanner was the most involved mechanic in the game which rewarded skill with increased speed of procurement! Very underrated bit of programming there. It did get a bit too much use with the Engineers, however!
Nice touch!
Hmm... I think if I continued, it would no longer be an entirely positive post! ;-)