Many moons ago on a forum far from here, I had a Fallout RP going with a buddy of mine. This was mostly set around the New York area and had my character, an Enclave separatist officer, diving into the Enclave and getting pulled into this brutal civil war after their defeat at Raven Rock in Fallout 3. My buddy basically was a synth from Massachusetts (keep in mind this was waaaay before Fallout 4 was even announced) who was escaping from her captors and enjoying the ride down the coast.

At the same time some people wanted to do New Vegas stuff so we set up NCR military policemen in an occupied New Vegas hunting down a gang or something. Although to be fair, the people playing the gangster duo were super Mary Sues and we were just looking for an excuse to shut them down a bit. The setting honestly wasn't as fun and inventive as our original characters.

Those could be some ideas.