What are your favourite free Copilot alternatives?

OpenAI Codex. It will probably be paid later too, but Copilot is built on top of Codex. I haven't found Copilot very useful myself; it's a bit too high level.

Codex lets me control outputs quite a bit. I've been mostly using it to convert content stored in spreadsheets. But it's also been useful in say, writing unit tests. I have a command prompt macro for it.

I think the biggest problem most people have is paying $10/month on Copilot, but I've been using GPT-3 extensively and never paid over $10/month.

Little by little, I've been trying to write a bit of code on my own here and there. I'm gradually getting better, and I have no doubt that I will meet and maybe even surpass the code quality that Copilot can output within a couple of years with consistent practice.