Hello from beyond the grave,
It is amazing (terrifying) that I recognized almost all these games by name, even the Japanese ones, from halfway across the room as bort scrolled through this thread. I am something of a D.U.N.G.E.O.N. C.R.A.W.L.E.R. E.X.P.E.R.T., specifically turn-based ones, so I hope you don't mind if I post a few of those. But I'll try to concentrate on action dungeon crawlers. . . . . . .

is the eldritch wizard eye or the scowling nord more menacing? that is for you, the player, to decide.

he earned his six pack by hammering on swords all day. you must earn yours through questing.

people who played the later elder scrolls games don't like the first two because you have to hold the right mouse button down and swing the mouse around. it can be difficult to get used to and probably gave some people carpal tunnel syndrome.
Elder Scrolls: Arena is one of my favorites. There is a lot of cool stuff about the game - the world is randomly generating and there is an infinite number of randomly generated dungeons. You can talk to people, get quests, go to dungeons, break into houses and spend hours agonizing over character builds. But the best things about the game, something that every single person who talks about it overlooks and something I probably spent more time doing as a kid, are the spells passwall and destroy floor. These spells straight up destroy the walls and floor. I'd go into dungeons or houses and cast these spells over and over to create my own dungeons. For me, the game was Minecraft 15 years before Minecraft was even a concept.

the chamber of the king of worms. he is not actually in the sarcophagus, the king of worms is the guy standing off in the shadows.

the world of daggerfall is humongous, apparently two times the size of great britain. the world has thousands of towns and dungeons and a bunch of different environments - mountains, swamps, desert, tundra.

an avaricious warlord dared to venture into the orc's abode... and is now paying the ultimate price.
Daggerfall is the sequel to Arena and is better in every single way (except there's no more passwall or destroy floor : ( ). The game has more content - hundreds of new quests and guilds and characters and ways to actually interact with it, but the most important thing is that everything in the world feels connected. When you join the wizard's guild and climb the ranks, guild members will treat you differently. If you kill and steal, people will call you a villain and spit in your face. But maybe people in the next province won't know about your crimes and you can start over.
The game's big problem, and maybe it's not a problem if you're into them, is that the dungeons are too big. Humongous. There are times when you're tasked with finding mummy wrappings or poppy seeds or some trivial item in a dungeon that is 20 square kilometers. Sometimes the dungeons aren't constructed properly and they're located in areas you can't actually reach. Once you reach your goal, you have to escape from the dungeon using an automap that is largely unreadable. It is both a lot of fun and extremely frustrating. Tread carefully youngster, for one man's treasure trove may be another man's grave.........................................................................

confronting your arch-nemesis khul-khum. stonekeep used early 90s digitized actors as 2d sprites to varying degrees of success. i think they look charming and i've always thought stonekeep's graphics were very good, but i can understand why some people wouldn't!

battling shargas. you'll deal more damage if you click on unarmored parts of an enemy's body, in this case the face and arms.

these are throgs and they always scared the hell out of me. they thump the ground really fast and hard when they run and they're always patrolling around for you.
Stonekeep is a game that took Interplay something like five years to make. By the time the game was completed, its once-revolutionary digitized graphics were already outdated. What wasn't outdated was its approach to dungeon design - it has some of the best dungeons of any dungeon crawler I've ever played... and I've played em all!!!!!!!!!!!!!!! What makes Stonekeep's dungeons good is that they're actually filled with THINGS. People to talk to, monsters with problems you can deal with, quests to do, puzzles to solve, objects to interact with. Even though the game is a dungeon crawler, it feels like you're in a place where monsters and people actually live rather than a place where you go to get treasure. It's also got secrets everywhere, more secrets than any other game I'm aware of. It is a lot of fun to discover them because a lot of the time they can dramatically alter the way you play. The game's story is pretty standard fare, but it's the places you go and the neat things you do along the way that make it truly exceptional.
this ridiculous face is on every single wall in this dungeon.
the best thing about realms of arkania: star trail is definitely its travel system, which is like a hardcore version of oregon trail. wear snowshoes and a coat in the winter or you'll get frostbite. clean your wounds after battle or you'll get tetanus.
the game is full of pop-up events where you're forced to make choices. my favorite pop-up, and maybe my favorite thing in a video game ever, is of this mountain goat who bothers you as you're traveling. you have the option of throwing something at it to make it go away. for years, i would throw different things at it to no effect, but one time i decided to throw licorice. when it ate the chewy licorice, it played an animation of its mouth getting stuck and then wandering away.
Realms of Arkania: Star Trail is a turn-based first-person dungeon crawler, so it's not really what you're looking for. But it's one of my favorite games ever so I'm going to post about it anyway!!!!!!!!!!!!!!
Star Trail is probably the most complex RPG that exists. You have a party of six characters, each with dozens of skills and spells that determine what they're capable of. Skills range from the practical, like sword fighting, thieving, social skills, medical skills and hunting, to crazy things like animal training, dancing and drinking, to bizarre skills that probably do things that I cannot actually figure out like danger sense, pain tolerance and ancient rituals.
The game is all about exploration. There is very little plot - go find the Salamander Stone!! - and throws you into it without telling you where to go. It is all about finding yourself in crazy situations and stumbling blindly from place to place with very little direction. There are events and things to interact with everywhere, the world feels very alive, and the way you use your skills to influence outcomes really makes your party composition feel important.
The game has both a prequel and a sequel and they are excellent games, but Star Trail is the best one and the one you should start with!
I know many more........................................... and I will post them soon.