I don't know, many of the games mentioned only really need higher quality textures and better lighting/shadows/global illumination. RT would be a cherry on top.
I disagree. Nearly every game mentioned here is upwards of two and a half decades old. You can't bring those anywhere close to modern visual standards with textures and lighting improvements. The polycounts of the assets are extremely small. The geometry of objects is primitive to say the least. Games like Hexen and Heretic (mentioned earlier)
aren't even 3D games at all.
In fact, retextures and lighting upgrades wouldn't help any of the games mentioned in this thread. Sure, they might look better than the originals, but they'd be far from good looking compared to modern games. Prey 2006 might be the exception, but everything else is far too old.
Dark Forces II Jedi Outcast & Jedi Academy are Quake III engine based games. These have primitive geometry. I have fond memories of these games looking really good now, but go back and look at them now. Retextures aren't going to fix them. We know this from the pathetic remasters of Quake and Quake II.
Pong, Zork and Pitfall were mentioned. These aren't 3D games at all. This almost had to be a joke. Textures and lighting upgrades aren't going to do anything for games like these. Starcraft is another 2D game. We might as well be talking about Pong.
X-Wing, TIE Fighter, etc. are 3D, but these are even primitive by Quake I standards. These games need entirely new assets. Which was done by a small team as a mod for one of the newer X-Wing games. X-Wing Alliance, I think. Rebel Assault I and II were made through a combination of primitive 2D/3D and digitized video. Again, you can't make a simple remaster of these and not be wasting your time. In fact, these are even harder to do than the 2D bitmap games as you can't just increase the resolution. We don't know the resolution of the digitized source video, but I doubt its good.
Soul Reaver was mentioned. I love that game but look at it objectively. Again, we are talking about a Gex engine game that's two decades old with primitive 3D modeling. Retexture it all you like but it's not going to look any better than the lazy Quake I remaster. That's all that's been mentioned. Mass Effect Legendary Edition mostly worked because the games aren't quite as old and due to various factors such as art style, etc. they've aged really well.
But we've seen retextures of games like Halo Reach which are far more modern than anything on this list and it just doesn't look that good. Sure, when you put images of it side by side against the original, you can see some nice improvements. The game is much improved, but more so for being setup to work on modern systems more than having upgraded visuals. Retextures are lazy. Hell, if its a UE3 engine game I can do that kind of work myself. The fact is that you can't overcome primitive asset geometry with ray tracing and some higher resolution textures. That's not how this works.