1. Exactly. 2. Absolutely. 3. That's so true. 4. That's for sure. 5. I agree 100% 6. I couldn't agree with you more. 7. That's exactly what I think. / That's exactly how I feel. 8. (informal) Tell me about it! / You're telling me! 9. (informal) I'll say! 10. I suppose so. (use this phrase for weak agreement – you agree, but reluctantly) Note: Avoid the common error of saying "I'm agree" – the correct phrase is "I agree" or "I'm in agreement" – the second one is more formal.
In spite of Chinas infamous ban on Twitter and other microblogs due to the governments concern about the rapid proliferation of information, Chaos microblogging platform managed to find favor with the powers that be due to his keenness on keeping information the government dislikes off the internet. His platform, known as Sina Weibo is now reaching 100 million users (Twitter has 200 million) and in spite of the censorship, Chao has managed to create one of the freest forms of expression in the country.