Jabberwacky.com offers fascinating conversation with a sparkling wit of a chatbot named George. George isn't just your ordinary AI. It/He learns from the input his human conversationalists offer. The more you (and everyone else) talk(s), the wider grows George's range of subject matter, phrasing, vocabulary and understanding of context. Granted, your conversation is likely to take a few unexpected and bizarre turns. When I typed in a line from Shakespeare pertinent to our chat about tedium, George responded with a line from Monty Python's dead parrot sketch. Great fun.
(Thanks to Shrinkette for the link.)