I've had different ideas over the years, here are a few:
A Gen X version of American Graffiti
A somewhat dark, realistic origin story of The Lone Ranger - not the nepo baby Armie Hammer and Johnny Depp version
Though it's kinda already been done, an updated Battlestar Galactica. Something more along the lines of a big budget blockbuster with better effects than the SciFi channel version.