As the one that started it all, ChatGPT remains a formidable and versatile contender. Powered by OpenAI's cutting-edge GPT-4o model, it excels at a wide range of tasks from creative writing and coding to complex problem-solving. Its major advantage is the vast ecosystem of custom "GPTs" that tailor its abilities for specific tasks.

• Strengths: Highly creative and fluent, massive library of custom GPTs, strong reasoning and coding capabilities, and multimodal input/output.
• Best for: Users who want a powerful, flexible, and highly customizable AI assistant for a diverse set of professional and creative tasks.

Gemini is Google's answer to ChatGPT and is deeply integrated into the Google ecosystem. Its biggest strength is its direct line to Google Search, providing real-time information and sources. With Gemini 1.5 Pro's massive context window, it's a beast at processing and summarizing large documents, videos, and codebases.

• Strengths: Real-time information from Google Search, huge context window for processing large amounts of data, and seamless integration with Google Workspace and other Google products.
• Best for: Researchers, students, and anyone who needs up-to-the-minute information or has to analyze and synthesize information from large documents.

Copilot, formerly Bing Chat, is Microsoft's AI assistant, powered by OpenAI's latest models. Its killer feature is its tight integration with Windows and the Microsoft 365 suite. It also provides free access to powerful models like GPT-4 and DALL-E 3 for image creation, making it a high-value proposition.

• Strengths: Free access to powerful models, integration with Windows and Microsoft products, and excellent for web-based research and image generation.
• Best for: Users who want a free, powerful, and convenient AI assistant for everyday tasks, research, and content creation.

Developed by Anthropic, Claude is designed with a focus on safety and producing helpful, harmless, and honest responses. It boasts a very large context window, similar to Gemini, making it great for analyzing lengthy documents. It's often praised for its more natural, conversational tone.

• Strengths: Strong emphasis on AI safety, large context window for document analysis, natural and conversational style.
• Best for: Users who prioritize AI safety and a more conversational interaction, or those needing to analyze long, complex documents like legal contracts or research papers.