I saw a similar thread on a different forum so I'm bringing it to MH. This thread is about discussing and showing real fighters that appear to be master class or super master class.
Ip Man, Bruce Lee's master seems to be a "super master": http://www.youtube.com/watch?v=zjJhNcLSuwQ&NR=1, http://www.youtube.com/watch?v=BwDzcE3mNco, http://en.wikipedia.org/wiki/Ip_Man
Here's a list of possible super masters from the past:
Morihei Ueshiba, Masutatsu Oyama, Gosho Motoharu,
Here's a list of other possible real life super masters from the distant past: Miyamoto Mushashi, Sasaki Kojiro, Yagyū Munenori, Itō Ittōsai
http://en.wikipedia.org/wiki/Musashi_Miyamoto, http://en.wikipedia.org/wiki/Sasaki_Kojir%C5%8D, http://en.wikipedia.org/wiki/It%C5%8D_Itt%C5%8Dsai, http://en.wikipedia.org/wiki/Yagy%C5%AB_Munenori
Muhammad Ali is definitely at least a high tier boxer, if not "master" level. Look at this! That's some sick dodging there.
I would consider Tony Jaa a master class fighter. Also Wong Fei-Hung is pretty well known as well.
Here's a clip of Mas Oyama fighting a bull: http://www.youtube.com/watch?v=Lyo4itn-y8w
Doppo Orochi from Baki The Grappler is based off him. Look up Doppo Orochi on youtube.
Regarding other styles, hard to say I don't keep track of many martial arts. I only know what hollywood has taught me =P
Well , in my opinion , I'd say Chuck Norris
On a serious note , I personally always believed that most people who have been called Gods were in fact experts at martial arts . There legend just kept on increasing and grew to the point that people started worshiping them .