Anthropic
anthropic.comAI
Claude's own maker — strong reasoning and long context, built with more thought given to safety than most.
Other products from AI
The default LLM API for a reason — GPT models, huge ecosystem, and every tutorial assumes you're using it.
Google's answer, with real native multimodal input and a free tier generous enough to actually prototype on.
European and more open about its weights than the US giants, usually cheaper too if that matters to you.