1) Ravenloft: Strahd's Posession - Castle Ravenloft
What made me really enjoy this dungeon was the lore, the oppressive atmosphere, the gothic theme, and the insidious encounter design.
When exploring around you'll come across pieces and bits of lore that narrate the true extent of Strahd's wickedness, his fall from grace, as well as his inner secrets that highlight the tragedy in his fall. Down in the depths you can find his personal diary, both it, and some notes, add much needed contextualization to Strahd's motives. It's important because it showcases that the Count has dimension to his character. I enjoyed reading the notes you can find scattered about, the writing is competently done in that regard. As for the enemies, the minions that stalk your every step, haunting you, reminding you that you're in Strahd's personal playground and he's not welcoming guests, is just fantastic. For instance there's a group of vampires who are just relentless in haunting you. In this game, Vampires incur permanent modifier to stats, that's right baby, those stats are permanently gone, welcome back to AD&D. They also take steal your levels too. On top of this, there's wraiths, and ghost knights that require magical weapons to hurt - its kind of insane because the game loves to spam these enemies in a group at you. The encounter design adds to that overall theme of hopelessness that Ravenloft is all about. Though in actual practical gameplay it's kind of easy since Ravenloft isn't a difficult game to play. However it's the idea behind the design that matters.
Though there's one thing about this dungeon that I really liked; and that's how you can stumble upon the Count himself down in the lower floors where his coffin is located at. You can trigger his boss fight very early. I personally found this hilarious because of how unexpected it is. I love it when games trip me up like this. If you don't have the holy symbol of Ravenkind, you won't be able to kill him. It basically means you'd do no damage to him. When I first encountered this I couldn't stop laughing hysterically. I remember hitting him over and over thinking my game was bugged until I learnt you need the symbol to actually hurt him, it was fun for me.
With all that said, the main reason why I still remember the game, the dungeon itself, is because of the beautiful gothic soundtrack that plays in the level. I still come back to it every now and then because of how pleasant it sounds to my ears, take a listen:
^that video is mine. I tried messing around with a few different MIDI soundfonts to make it sound better but it's toss up if it's any better
2) Ravenloft: Stone Prophet - ???
This game will always hold a special place in my heart. Stone Prophet means a lot to me. I love this game. I truly do. However it's hard to pick a specific dungeon that I liked the most, hence the question marks, since they're all wonderful to explore. The music. The middle eastern themes that appeal to my Moroccan heritage. The puzzles. The loot. The exotic companions. Stone Prophet evokes a warm comfort that I rarely experience in gaming. Each time I jump back into it I feel like I'm at home exploring the Har' Akir desert. I guess if I had to pick one dungeon, it's probably going to be the Burial Grounds. Mainly because you get to find an undead paladin waifu in it - how many games let you get an undead paladin waifu, how many, none, absolutely none. She's the best! Though she passes on to the after life once you successfully destroy the evil that has cursed her into the undead state. In the time you do get access to her, she's super strong. Since she's undead she doesn't require water to drink, which is kind of huge since in Stone Prophet you need to manage water consumption else your party will get a loss to stats then die. She also gets a magical weapon that alleviates combat - it doesn't really matter though since the Ravenloft games are ridiculously easy to beat. I usually get her then do the other dungeons saving her quest for last since I love having her in the party for as long as possible.
Of course, can't talk about Stone Prophet without mentioning the music. I simply adore the music in Stone Prophet. I really do. Here's a few tracks:
Also, can not forget the legendary vocals that plays in the illusive Ghost song:
^the lyrics she cites are a riddle for a dungeon you need to find it's pretty great stuff - i cheated and referenced the cluebook because me am no big brain