I love dungeons and I love dungeon crawling too.
I started playing and DMing in dungeons, I'm still there and surely I will do in my future.
Many don't like dungeons. They think about them as an old way of gaming, which restrains players too much, forcing their choices and substantially negating free will to players.
Well, in my opinion they're simply wrong.
We can divide in three part every scene of a dungeon, considering every dungeon room a "scene": exploration, interaction, decision.
Exploration is simple: the party comes in a room and starts to realize what's inside. You describe the room and give extra details, aswering to players' questions.
Now think: what's happen outside a dungeon? When party enters a tavern or reach a marketplace, a warehouse, a campfire, a castle, a bridge, a ford....anything you want...what's happen? The same.
At this point PCs begins to act to according to their goals, their behaviours and circumstances. They talk with people, search for clues (secret doors, traps..), try to interpretate signs (writings, tracks, stains..), fight with monster or enemies.
Now think: outside the dungeon, PCs do the same things, don't they? They look for informations (talking to people, tracking, looking into ancient books) and fight against monsters and enemies.
According to the output of their interactions, PCs make decisions, which lead them to more interaction or to a new room (a new "scene), where a new exploration begins.
Now think: the same happen outside. They go to a tavern, talk to someone, then after the talk decide to go elsewhere. They enter a thieves' den, fight and kill them, then tgere they find a message and decide to go to the harbor, looking for a specific ship. It's the same, isn't it?
Yes, it's the same.
What I want to say it's that in a fantasy game (expecially in D&D games) all the world is a dungeon and the dungeon is the world.
Players' free will isn't tied to adventure's location but it's up to the DM.
A DM should have skills to modify and expand a scene, reacting to party's explorations, interactions and decisions.
More he has these skills more free will have the players.