What Are The Best Intelligent Chatbots or AI Chatbots Available Online?

How do we define the intelligence of a chatbot? You can see a lot of articles about what would make a chatbot "appear intelligent." A chatbot is intelligent when it becomes aware of user needs. Its intelligence is what gives the chatbot the ability to handle any scenario of a conversation with ease. Are the travel bots or the weather bots that have buttons that you click and give you some query, artificially intelligent?