Imagine Watcher's Keep with 10 levels, in each level you solve puzzles, learn more about the story of the place, interact with the inhabitants, have challenging combat encounters . How about a small town inside the dungeon, a interesting boss like Demongorgon in the end, maybe factions to form alliances. The dungeon is alive and is a believable place. This is what I hope.
My nightmare:
The only possible NPC interaction is: Should I kill this orc/darkspawn/Draug with a mace, a sword or an axe?
The levels: No variation. How many shades of grey those caves have?
Puzzles: Puzzles? There is no space for puzzles in modern game design. Today gamers only like to kill stuff, right?
Linearity : Why I have a map , if I can't get lost?
The end boss is: Just a bigger orc with a funny hat.
Combat encounters: I just killed the whole orc race.
Story: What story? You don't need it. Here, more stuff to kill.