anata is a basic form of "you". It is a bit personal to use with strangers or simple acquaintances. When refering to someone else, you would use their name instead of a pronoun.
omae (lit. person in front of me) is a fairly strong version of the word "you" and is used with either a close friend (only male as a rule) akin to calling a Western friend of yours 'jackass,' as in 'hey jackass, lets get some pizza.' When used with a stranger or in anger, it is about the strongest way of addressing someone without being directly offensive.