neovim with the gp.nvim plugin.

Allows you to open chats directly in a neovim window. Also, allows you to select some text and then run it with certain prompts (like "implement" or "explain this code"). Depending on the prompt you can make the result appear directly inside the buffer you're currently working on. The request to the ChatGPT API also is enriched with the file-type.

I hated AI before I discovered this approach. Now I'm an AI fanboy.