I've been diving back into Ghost Recon Wildlands after discovering just how damn enjoyable the game is at the highest difficulty levels. Suddenly sniper rifles and stealth are the only viable playstyles, and I feel like I'm actually being tested by the AI rather than watching all these paper narcos obligingly fall over and die for my amusement. I also love how unwoke the game is. Very America Fuck Yeah.
I also dusted off Master of Magic. Still haven't found a 4X that rivals it in my eyes, and it's not nostalgia talking. I actually never played it growing up (though I played MoO and MoO2 like my childhood depended on it). Good shit.
There is a fan-made DLC that GOG has started selling called "Caster of Magic." I don't really know much about it. People seem to love or hate it. There's also an HD Java-powered MoM version that's surfaced in the past year. Haven't tried that either.