恭喜发财, apparently.
Kung Hei Fat Choi? (well that's what Google claims is the English translation

). I think it is a wish for fortune and prosperity but it's not one I've heard being used much.
Nónglì Xīnnián in Mandarin. Don't ask me how to pronounce that though!
I think that is more the description of what day it is. It would be like saying "Solar Calendar New Year!" on January 1st.
I'm currently chilling in a cafe in Yunnan Province and the phrases used around here are 春节快乐 (Chun Jie Kuai Le) or 春年快乐 (Chun Nian Kuai Le) both of which wish you a Happy Spring Festival (The better translation for Chinese New Year). You can also get away with the more general 新年快乐 (xin nian kuai le) which just means Happy New Year (but is also used on Jan 1st).
I'll point out that Chinese New Year is seriously ****ing crazy here in mainland China. A former colleague once referred to it as "National Try To Kill Yourself With Fireworks Week". At 12 last night it sounded like a war had started!