Easier-to-run 4k games?

Recently got a 4k monitor for a great price, and itll be running on a single 980ti and an i5-4690k for my secondary build, until i can upgrade the GPU to something that can push more recent games at 4k.

What im asking, is what are some games that the rig will be able to run at 4k, even if i turn down some settings to hit 60fps? I dont care if they're super modern AAA games, I like everything from city building to old fallout games to Rpg games! Looking for suggestions!