Undoubtedly, the ever ruthless and vicious man, President Snow, would quite fit the bill as the creator of the Hunger Games and he certainly has carried forward the sinister legacy to the best of his capacity during his reign. But one can say with certainty that Snow couldn't have been the creator of the Hunger Games.
The Hunger Games Wiki claims that President Snow is 76 years old. So unless he became the President of Panem at the age of two or three and conceived the Hunger Games in his infancy, and that is as unlikely as it sounds, there was someone else in charge when the uprising took place consequently leading to the evil tradition of the Hunger Games which later evolved under different Head Gamemakers.
If Suzanne Collins has left that to our imagination, I think someone who has read the trilogy thoroughly can possibly try to connect the dots, gather the missing bits and pieces and deduce something relevant?