All the main IDE-integrated ones seem very much on par (Copilot, Sourcegraph Cody, Continue.dev), with cursor.sh liked by some as it has code assistant-first UI.
I've personally went back to the browser with Claude 3.5 Sonnet (and the projects + artifacts feature), as it is one of the most industrious ones, and I really like the UX of artifacts + it integrates new code well into existing code you paste into it.
In the end I think it also often comes down to what languages/frameworks you are using and how well the LLM/product handles it, so I'd still recommend to test around. E.g. some of the main frameworks I'm working with on a daily basis went through big refactors/interface changes 1-2 years ago, and I stopped using ChatGPT because it had a strong tendency to produce code based on the old interfaces/paradigms.
Aider[0] is also quite interesting, especially when it comes to more significant refactorings in the codebase and has gotten quite good with that with the last few bigger model releases, but it takes same time to get used to and doesn't have good IDE-integration.
I've been following the state of things, but I'm not sure which ones are the best. There's Meta's CodeLlama[1], Mistral's Codestral[2], DeepSeek AI's DeepSeek-Coder-V2-Instruct[3], CodeGemma[4], Alibaba's CodeQwen[5], and Microsoft's WizardCoder[6].
I'm pretty sure CodeLlama is out of date now. I've heard DeepSeek LLMs are good and DeepSeek-Coder-V2-Instruct was released recently. With the good reputation and its massive size (236b) I'd guess it is the best coding LLM, but if it's not being trained efficiently, maybe Codestral and Codestral Mamba come close.
I don't think the best coding LLMs are close to GitHub Copilot but I could be wrong since I'm just relaying information that I've heard secondhand.
