Mostly Gemini 2.5 Pro lately.

I get asked this often enough that I have a FAQ entry with automatically updating statistics [0].

  Model               Tokens     Pct

  Gemini 2.5 Pro   4,027,983   88.1%
  Sonnet 3.7         518,708   11.3%
  gpt-4.1-mini        11,775    0.3%
  gpt-4.1             10,687    0.2%

[0] https://aider.chat/docs/faq.html#what-llms-do-you-use-to-bui...