Rogue Survivor won't wait up for you. If you manage to stockpile tons and tons of food on day 2 and chill in your safehouse for a couple weeks, you'll walk out to see a world where all the furniture is destroyed, remnants of National Guardsmen, Bikers, Gangstas, all sorts of people running like hell, whole zombie hordes of high-level zombies being lead around slaughtering everything that moves, all initial resources stripped clean... It's quite the chaotic world.
It's the most appreciated game type around here, too: Roguelike.
I'm not 100% sure this is the type of game the OP is asking for, but if it is, he might want to look into Project Zomboid, which should end up very much like Rogue Survivor, except with an isometric view. Though the world right now is not yet quite that dynamic, the dev's goals include having NPCs team up together and build their own safehouses, zomby hoardes migrating depending on availability of fresh meat and spreading of noises, army intervention happening after some time, power being cut off once the local power plant succumbs, etc. All with no intervention by the player.
Now that's exactly the sort of thing I'm looking for! However, an important bit is that it ought to vary from time to time (getting to that).
Rogue Survivor won't wait up for you. If you manage to stockpile tons and tons of food on day 2 and chill in your safehouse for a couple weeks, you'll walk out to see a world where all the furniture is destroyed, remnants of National Guardsmen, Bikers, Gangstas, all sorts of people running like hell, whole zombie hordes of high-level zombies being lead around slaughtering everything that moves, all initial resources stripped clean... It's quite the chaotic world.
It's the most appreciated game type around here, too: Roguelike.
Now that is a good game, but the numpad movement keys annoy me somewhat. I haven't played it in depth, but I will in a while.
The X games are somewhat open (traers trade races fight) but i don't think sectors can be conquered.
I remember the Military hunting pirates and poping pirate bases.
The X series is great fun, but it isn't (especially) dynamic. The markets fluctuate (I think), you can make an enormous fleet scouring the galaxy for pirates, and certain mods improve things a bit, but if you chill out doing nothing not much will change.
Star Control 2 or the free open source port The Ur-Quan Masters. Events progress regardless of whether you take part. I can't say too much without ruining the plot. It's one of the few games who's writing I really enjoyed.
I love SC2, but an important thing about dynamic worlds (in my opinion) is that the game world should evolve through interactions between NPCs rather than set events occurring. In SC2, the exact same set of events occur regardless of your interventions (barring a handful of exceptions where you call in other races, which only delay things a bit).
How different is Warband singleplayer vs vanilla Mount and Blade? It seemed pretty much the same when I played them. There's some evolution, but somehow I feel it never realised its full potential.
Very different fighting style (Warband is more fluid if you know what I mean), and the AI in Warband is a bit smarter when it comes to conquest. Still, Warband would be better if each individual lord went out and had the initiative to attack castles/cities and the patience to not run away after a couple days' siege. Usually only a handful of castles switch sides over time because the only time anything gets done is when the king leads a big mob at a lone castle, and even then they don't prioritize border territories.
Also, I guess I might have to try Space Rangers 2 again... somehow I felt I had stagnated not too far into the game. Perhaps I was playing it wrong.
Space Rangers 2 is a great game, but it was translated quite poorly.