>>3
Oh gawd plz don't even CONSIDER Chinese unless you are really dedicated. Not only is kanji (hanzi, in this case) a pain in the ass, but speaking and listening is a nightmare if it's not your native tongue. And apart from showing off at your local Chinese restaurant, you will probably not have much use for it because of the relatively low output of pop-culture from China and Taiwan when compared to Japan. And don't plan on using it in business contexts, there are plenty of overseas immigrants with better-than-passable English to take that spot. 相信我說的話，學中文學得不好玩。
And yes, what the others say is also true, don't bother with Japanese either unless you're serious about it. If it's just for cursing, German sounds equally cool.