Here are some of the best AI Dungeon alternatives in 2023:

ShortlyAI is a free AI text generation tool that is similar to AI Dungeon. It can generate text, translate languages, write different kinds of creative content, and answer your questions in an informative way.
Dreamily.AI is another AI text generation tool that is similar to AI Dungeon. It has a variety of features, such as the ability to create custom characters and settings, and it is also able to generate NSFW content AI Dungeon alternatives.
Write Holo is a relatively new AI text generation tool that is still under development. However, it has a lot of potential, and it is able to generate text in a variety of different styles.
Philosopher AI is an AI text generation tool that is designed to help people with creative writing and problem-solving. It can generate text in a variety of different styles, including poetry, code, and scripts.
NovelAI is an AI text generation tool that is designed specifically for writing fiction. It has a variety of features that are helpful for writers, such as the ability to create character profiles and plot outlines.
In addition to these AI text generation tools, there are also a number of other games and tools that can be considered alternatives to AI Dungeon. For example:

Dwarf Fortress is a complex text-based simulation game in which you build and manage a dwarf fortress. It is known for its difficulty and its depth, and it can be a great alternative to AI Dungeon for players who are looking for a challenge.
Cataclysm: Dark Days Ahead is another complex text-based game in which you survive in a post-apocalyptic world. It is known for its realism and its challenge, and it can be a great alternative to AI Dungeon for players who are looking for a survival game.
Project Electric Sheep is a realistic dream simulation game. It is a great alternative to AI Dungeon for players who are interested in exploring their dreams.
I hope this list helps you to find an AI Dungeon alternative that you enjoy.