When you're looking for a familiar set of rules for your RPG, the D&D rules are a pretty good one to go with. I think it's safe to say that most gamers are familiar with it. But if you're looking to play in something other than a fantasy realm, you're going to need some help. Like, if you want something modern, you'd look to d20 Modern. Well, Everyday Heroes is the spiritual successor to d20 Modern, including setting guides for some pretty iconic movies. You can find it all up on Kickstarter now.
From the campaign:
Everyday Heroes™ - The spiritual successor to d20 Modern, now based on 5th edition (the most popular RPG system in the world) and set in eight amazing campaign settings based on the world's most beloved movie franchises.
Twenty years ago, d20 Modern was launched and grew to become the most successful modern-day TTRPG in history. We brought back some of those original designers to create Everyday Heroes™ - a 5th edition refresh of the historic d20 Modern. If you were a fan of d20 Modern, you're not going to want to miss this upgrade. If you don't know what d20 Modern was, then get ready to take the leap.
The campaign's around 15x funded with 24 days left to go.