The fallout game of my dreams would keep the gameplay of 1/2 but greatly expand the amount of actions you could take in combat. Whack someone with the butt of your gun, quick fire from the hip, stomp downed enemies in the face, that sort of thing. Additionally, it would be cool if your actions (and those of the enemy) played out up close and with gruesome detail. Kind of like the cinematic aspect of VATS, but not so boring and repetitive. More unique animations and stuff.
Also, I’d love it if dialogue was expanded. The dialogue options in the originals are sometimes sparse and lackluster. Ideally, for every conversation you’d have 5 or 6 (more or less, depending on what’s feasible) potential responses, each tailored to a different kind of personality type.
I’d like to bring back the world map too, and have it require food and water in order to travel on it.
As far as an original IP goes, I have lots of ideas, and one of them is particularly fallout-inspired. It’s setting is pretty similar to cyberpunk 2077 (though I had this idea long before I knew about the cyberpunk IP) in that it would take place in a giant city surrounded by post-apocalyptic desert. In much the same way fallout is based on the world of the 1950s, this IP is based on the world of the 1970s. Heavy influence from exploitation films of the 70s and 80s, stuff like Dirty Harry, Taxi Driver and Death Wish, mixed with the dystopian/sci-fi of movies like Mad Max, Robocop, and Escape from New York. Anyway, this city would be controlled by 2 major factions: the evil corporation that founded the city and has a monopoly on pretty much every legal product, and the overzealous police force that tries its best to establish order. Beyond these two factions, the rest of the city is run by various crime families and gangs. It would kind of be like a three-way power struggle to control the city. Anyway, I have more but this post has gone on long enough.