Monica is the most complete AI all-in-one assistant on this list. It runs as a Chrome and Edge extension and as a standalone web app, giving you access to GPT-4o, Claude 3.5 Sonnet, Gemini, and Mixtral in one place. Features include AI chat with web search and citations, PDF and document summarization, image generation, translation, a writing assistant, and a browser sidebar that works on any page you visit.It earns the top spot because it delivers the widest feature set at the lowest entry price. At $4.1/mo you get real, usable functionality — not a crippled demo. The $24.9/mo Pro plan removes daily caps and adds priority model access for heavy users.Best for: Individuals who want one tool for writing, research, summarization, image creation, and chatPricing: $4.1 – $24.9/moHonest caveat: The free tier enforces strict daily message limits and you will hit them fast. The sheer volume of features can also feel overwhelming in the first week — it takes a little time to learn what lives where.