Lantander

The map of Faerun might make no sense to an earth geologist, but if one would ask a sage in the forgotten realms he could tell you why and how it is how it is... There are large deserts created by death magic (underground phaerimm activity that destroyed Netheril), Jungles lived in and expanded by Yuan-Ti praying to Zehir, large marshes caused by powerful spells (the kilmaru swamp in Haluraa), rivers flowing out of portals to the plane of water, giant rifts in the land where parts of the underdark collapsed - and of course all kinds of other things caused by actual gods walking the planet. I'm happy with pretty mixed-up landscapes - as long as the developers think up a reason and nice story why the land looks like that.

Some respawn would be ok, as long as it's within the bounds of reason. I don't just mean putting the same kind of monster somewhere every time, but... if you hack a gang of bandits to pieces, you could expect a dire wolf feasting on the remains when you come back next time. Or have another group of bandits move into the territory _once_ or at maximum twice. Just refilling encounters endlessly with the same monsters leads to something I hated in Fallout 3 - there you have... 30 or so friendly npcs in all of the settlements in total, surrounded by limitless numbers of raiders and deathclaws. After killing 200+ raiders and lots of deathclaws, you have to wonder why they pack their bags and come into the raider death zone from far and wide - and how the hell any friendly npcs are still alive with dozens and dozens of three meter tall clawed monsters roaming about. At some point, intelligent enemies should have the thought "The last five bandits who went to ambush people near <player>'s keep/village of X/... got wiped out, I'm going somewhere else - I want to live!". And barring a wizard summoning/creating lots of monsters or someone shipping in creatures from somewhere else, there is an upper limit of population density for huge predators - lone predators they usually have their own areas and if you kill one, its neighbour might move in - but once that one is dead too, there just are no more nearby who could fill its spot.

I'd prefer if the dungeon wasn't a thing you have to do in one continuous go. Realizing 10 lvls down that you're about to run out of arrows, food, etc. - and then having to trek up through empty hallway after empty hallway upwards will get boring pretty quick. How about this - you find the dungeon, explore it in the early/mid-game and fight your way downwards 4 lvls or so - and then run into someone/something that made its own entrance. Let's say... the cultists of the imprisoned demon lord deeper down, who tunneled directly into level 5 to bypass all the traps and monsters you went through. You kill them, and from then on can use the tunnel to come in and out (with the entrance on the surface in a dark forest far from any settlements). Going down further is blocked by a magical barrier that stopped the cultists and which you too can't get through until in the mid-game. At the point you find the power/item/ritual to open that, you can just take the tunnel and go in and start at exploring lvl 6. Then at lvl 10, you reach another thing to stop you (divine guardian/barrier/whatever) and maybe an ancient teleporter circle which can be repaired to link to ruins in a desert a fair bit off the normal roads. That way, the mega dungeon can stay interesting during the whole playthrough of the game... sections for different level ranges with a limited number of entrances (none of which leads to a vendor's house or the same location).