Doom 3 was a big flopza for me. NuDoom was far, far better. Only think Doom 3 had was nice tech for screenshots. I don’t even remembering it looking amazing in motion.
Yeah, it wasn't the great [outside of the tech], but it was definitely a radical departure for the series.
Oh, and I just remembered the obvious #1 game for that category: Fallout 3. To this day, people get salty about how much of a departure it was from Fallout 1 and 2. God of War 2018 is just the Tomb Raider 2013 of the series. It does have some differences, sure, but it's really just improving on the established formula and giving it a "serious drama" story. Nothing particularly radical about that, to me.