Mass Effect would be the obvious choice for me.
It's kind of bizarre that it doesn't have a TTRPG already, despite a lot of fan attempts. Sadly most of the fan attempts decide to randomly abandon major elements of the setting/lore/technology for reasons unclear, and/or have pretty terrible rules. I made an attempt with Cortex Prime, which worked pretty well, but I think it would have worked a lot better with a system specifically designed for Mass Effect. It has a well-developed setting with multiple time periods and areas within that setting which could be used, clear species and classes, plenty of foes, well-established and very "game-able" technology, and so on, so just seems like a no-brainer.
It did get a boardgame this year, which was bizarrely misreported as an "RPG" a bit (I blame AI) but still no actual RPG. I'd rather no RPG than it being given some clumsy existing system which was ill-suited for it though.