For Total Annhialation section: https://zero-k.info/

Zero Knhas been in active dev much longer than BAR, is more mature, has a well-established little cult community, and IMO is the better game. And still OSS ofc.

You really think Skyrim belongs there? I’d agree that Elder Scrolls deserves a place, but what did Skyrim do that wasn’t done by Oblivion or even Morrowind?

If influential means influencing game design / the industry, inspiring other creators by demonstrating novel ideas, I’d probably have to say Doom or Half-Life. Doom really showed what an FPS could be and kicked off such a dominant genre. Half-Life introduced immersive storytelling that greatly influenced FPS and non-FPS games.