In the entertainment industry we see a lot of remade movies and music covers of old songs, but we never see an old video game being remade, I have a few games that I love which are old and I think would be a lot of fun playing them again but in a new version using the most recent technologies available and I believe if done right they would sell again.
I have come up with a few games I personally would like to see remade, these are old quest/advanture games I played that have good story and beautiful scenary which would look amazing using modern technology, the games are:
Phantasmagoria, Sanitarium and Atlantis The Lost Tale, I will exaime what I think can be done with each game.
Let's begin with
Phantasmagoria 
Phantasmagoria is a 1995 Sierra quest thirller game which has a story about an old mansion called "
Carnovasch Estate" which have 3 or more floors, many unique rooms, big gearden outside and deep past. The game was made using live actors embedded into 3D model background of the home itself and other places you visit in the game.
Above is a picture of how the original game looks like, I would love to see this game in 3D engine being able to freely walk around and look at everything from first person point of view, I think the original game used a pre rendered 3D model of the mansion and all the rooms so maybe this model exists somewhere and can be used and updated to help remake the game and to keep it as close to the original in terms of unique rooms and the details in them.
I'd like to see Phantasmagoria game remade using todays latest and greatest grpahic engine to make it look as real as possible, and in the remade game I'd like to be able to walk around using first person view, the game will have the same plot, characters, everything the same only using the most modern technology in graphics and audio.
I think this way if done right, Phantasmagoria will be ever more thirlling than the original game and more fun to play.
Sanitarium, the game was released in 1998 and it's about a man who lost his memory and through the course of the game is trying to understand who he is, what happened to him and why, the game has a beautiful story and a lot of amazing sets which the character is going through, from a
mental tower to a
abandoned town,
circus and more interesting locations which would be astonishing if brought to a state of the art graphics engine.

This is a screenshot of the first level of Sanitarium, I imagine how this level woud look like in first person view in a high detailed 3D graphics engine.
Atlantis The Lost Tales game from 1997 about the mystic city of Atlantis before it has disappeared, the game takes place at amazing locations such as the
city itself,
beautiful forest, beaches and more the game has a lot of interesting details and concepts such as the device airplane like called "Flyer" which the people of Atlantis use to fly and fight, the story itself is very good.

This is an ingame screenshot of Atlantis The Lost Tale which still looks beautiful today but could be a lot more beautiful today, also the original game never let you freely walk around to every bit of place you wanted to go so I would love to have this possibility in a remade game of Atlantis.
Atlantis itself had good visuals for the year 1997 and I think it deserves to even get more detailed with todays high definition graphics.
To sum up, I would like to see these games remade into a new game which is exactly based on the old but using todays latest technologies to remake it, which means state of the art graphics and sound and possibily adding new gameplay options such as first person view for games like Sanitarium and Phantasmagoria but keeping the option for the classic gameplay style the original game had. I am sure there are many more old games that are worth remaking with the same principles, the games I wrote about here are my personal favorites that I played many times over.
By the way, if you haven't played one or all of these games consider this my recommendation for you to try them, they are good game if you are interested in story based adventure quest game.
I have posted this idea in gaming forums that I visit.