https://github.com/huggingface/chat-ui - Amazing clean UI with very good web search, my go to currently. (they added the ability to do it all locally very recently!)

https://github.com/oobabooga/text-generation-webui - Best overall, supports any model format and has many extensions

https://github.com/ParisNeo/lollms-webui/ - Has PDF, stable diffusion and web search integration

https://github.com/h2oai/h2ogpt - Has PDF, Web search, best for files ingestion (supports many file formats)

https://github.com/SillyTavern/SillyTavern - Best for custom characters and roleplay

https://github.com/NimbleBoxAI/ChainFury - Has great UI and web search (experimental)

https://github.com/nomic-ai/gpt4all - Basic UI that replicated ChatGPT

https://github.com/imartinez/privateGPT - Basic UI that replicated ChatGPT with PDF integration

More from the comments (Haven't tested myself) :

https://github.com/LostRuins/koboldcpp - Easy to install and simple interface

LM Studio - Clean UI, focuses on GGUF format

https://github.com/lobehub/lobe-chat - Nice rich UI with the ability to load extensions for web search, TTS and more

https://github.com/ollama-webui/ollama-webui - ChatGPT like UI with easy way to download models

https://github.com/turboderp/exui - very fast and vram efficient

https://github.com/PromtEngineer/localGPT - Focuses on PDF files

https://github.com/shinomakoi/AI-Messenger - Supports EXLv2 and LLava

Documentation - Vercel AI SDK - NodeJS/Reactive

FreeChat - some love to MacOS

Sanctum - another MacOS GUI

r/LocalLLaMA - Reddit

Mutate - Play

Home - Soba: Make games without coding