I don’t know who definitively believed it, but off the top of my head I can guess Jesus Christ, Hercules, Alexander the Great. I know at least one modern day psycho, was it Charles Manson?
Cites if possible!
Didn’t David Koresh beleive he was the Second Coming? Or a sign of Him?
(Taking side bets for post # that mentions what 49% are going to say) 
Emperor Hirohito of Japan was considered a deity until his surrender.
Was Hercules based on a historical figure? I thought he was purely myth.
Kings and emperors in MANY cultures were believed to be divine, or at least presented as divine for consumption by the masses. Take the Egyptian Pharoahs, for instance. Now, maybe the saner ones privately did not regard themselves as such, but I’m sure a lot of them were fully convinced they were deities, much like modern day celebrities who come to believe their own press releases.
Oh, I almost forgot. Did Buddah consider himself a deity, or just a philosopher?
The Buddha definitely didn’t consider himself a deity. Moreover, neither do Buddhists.
Wikipedia to the rescue again
great 
Looks like Wikipedia is the new google. Thanks for clearing it up.
Yep! hehe. I actually just created an article for this topic and already got another addition. See List of people believing themselves deities.
Someone added Vespasian and said his last words were "“Alas, I believe I am becoming a god!”
This gets parroted a lot and it shows a great misunderstanding of Shinto religion. Shintoism is close to animistic beliefs in that it holds that everything is a deity, in Japanese, “kami”. The Emperor is a deity. You are one also, and so am I. Mount Fuji is a deity, as is the pebble in your shoe, and the sun and the tree in your back yard, and so on, ad infinitum.
However, not all kami are equal and some, like, say, Amaterasu kami of the Sun are more worthy of worship than others. Someone once said Shintoism is the worship of all things great.
Now, of course this world view has been used for political gain since, well, since records go. In the admitedly very special case of the emperor, this first emperor of Japan, the mythical Jinmu is said, in ancient legends, to have litterally descended from heaven. From this follows that the emperor holds heavenly authority and since heaven is a place of absolute purity and perfection, the emperor is infallible.
That heavenly infallibility was used by the millitary puppet masters to either give legetimacy to their actions or to act as a beacon for hard nationalism and it is what was renounced by emperor Showa after WWII.
Saying that the Japanese emperor is “not a deity”, to a Shintoist, is like saying “the Pope has no soul” to a Catholic; it makes no sense.
Jovan, do those who practice Shinto then consider themselves to be deities? It sounds like it from the article.
Reverend Sun Myung Moon believes he is the reincarnation of Jesus.
The Buddha believed himself to be an Enlightened One – i.e., someone who had come to a realization about reality and the nature of human life within it that brought him to a higher, enlightened plane, and which he was willing to teach to others.
Buddah, on the other hand, considered itself to be, not a deity or a philosopher, but a record company!
alterego: yes. However, as you might have learned from the Wikipedia article, purity is very important in Shintoism. As long as you are a living human you are always impure to some extent. The proof of this is that you decay, grow old and die, while kami are eternal. Death, however, allows you to free yourself from this impurity. Thus, after death, all that remains is your divinity. It’s not the same thing as a soul as the only difference between, say, my dead uncle and Amaterasu is one of degree, not of nature.
After your death some people may decide to worship you. They might build a shrine for you, which may be nothing more than an empty box on a pole on the side of the road, or a huge complex covering many acres. This shrine then becomes your actual dwelling place. Shintoists really believe that kami litterally reside in their shrine.
Emperor Showa’s declaration was drafted by an American and it’s probably not unfair to say that it was as much intended for an American audience as for a Japanese one. To the Americans, it sought to say: “the big bad days are over” and to the Japanese: “I’m not different from any of you, and it’s not my destiny to subdue the world.”
Polycarp:
Nitpick: He was willing to teach others how they could find enlightenment for themselves. You cannot teach enlightenment not anymore than you can teach virtuosity. You have to practice it yourself.
There have also been several people, including a modern politician or two, who have believed that God speaks through them. That’s probably a separate category from deities.
Yes, that’s an iffy one as the Pope is “Christ’s representative on Earth”!
Prophets?
Yes, certain of the Roman emperors were deified on their death but I’m sure few of them (save Caligula) took it seriously, witness Vespasian, who commented in his final illness, “Oh dear, I think I’m becoming a god!”
Isn’t “oh dear” a rather modern phrasing?
I found a neat one with the google search “self-proclaimed deities”:
Kenyan ‘God’ sent Aids as ‘punishment’. Some guy named Jehovah Wanyonyi who thinks he is a deity, and is worshipped as such!