San (さん, San) is the most common honorific title, used when addressing most social outsiders, for example, non-family members.
San is often translated as "Mr.", "Ms.", "Mrs.", and the like. San may also be used in combination with things other than the name of the person being addressed. For example, a bookseller might be addressed as honya-san ("Mr. Bookseller") and a butcher as nikuya-san ("Ms. Butcher").
Kun (君, Kun) is an informal and intimate honorific primarily used towards males (It is still used towards females, but rarely.) It is used by persons of senior status in addressing those of junior status, by males of roughly the same age and status when addressing each other, and by anyone in addressing male children. In business settings, women, particularly young women, may also be addressed as kun by older males of senior status. It is sometimes used towards male pets as well.
Chan (ちゃん, Chan) is the hypocoristic suffix, used to refer to children, animals, and people whom one has known since they were children. To use chan for adults whom one has not known since their childhood requires considerable intimacy, less for women than for men. Furthermore, attaching chan to a modified stem is more intimate than attaching it to the full form of the basic name. Chan may also used for celebrities as a title of affection.
Senpai (先輩, Senpai) is used by students to refer to or address senior students in an academic or other learning environment, in athletics and sports clubs, and also in business settings to refer to those in more senior positions.
Kōhai (後輩, Kōhai) is the reverse of this. It is used to refer to or address juniors, though it might be considered somewhat insulting or overly condescending in some circles to refer to someone as kōhai directly.
Sensei (先生, Sensei) (derived fromMandarin Chinese xiān shēng, meaning Mister) is used to refer to or address teachers, practitioners of a profession such as doctors and lawyers, politicians, and other authority figures. It is used to show respect to someone who has achieved a certain level of mastery in an art form or some other skill.
Sama (様, Sama) is the formal version of san. This honorific is used primarily in addressing persons much higher in rank than oneself and in commercial and business settings to address and refer to customers. It also appears in words used to address or speak of persons or objects for which the speaker wishes to show respect or deference, such as okyaku-sama (customer) or Tateishi-sama (a stone revered as a deity).
Shi (氏, Shi) is used in formal writing, and sometimes in very formal speech, for referring to a person who is unfamiliar to the speaker, typically a person known through publications whom the speaker has never actually met. For example, the shi title is common in the speech of newsreaders. It is preferred in legal documents, academic journals, and certain other formal written styles. Once a person's name has been used with shi, the person can be referred to with shi alone, without the name, as long as there is only one person being referred to.
There you have it folks, enjoy!!!
info found using wikipedia 2006 edition (or check website)