my opinion is that supreme leader snoke from the force awakens is actually emperor Palpatine, there is more evidence than you think.
1. Snoke describes the fall of the galactic empire as Vader's fault due to his ties to his son, the reason he said this is that it was his downfall and he is teaching Kylo Ren (the son of Han Solo and Leia Skywalker, Vader's daughter) to not be weakened by his ties to his family.
2. Snoke's physical appearance is similar to Plpatine, wrinkled and decrepit, and the scars on his face look like something caused by force lightning and had been there for about 60-70 years, now, if you remember, in episode III, Mace Windu deflected Palpatine's force lightning at his face causing a lot of pain on his face, coincidentally, the scars on Palpatine's face are similur to that of snoke's, and the scar going down his face could easily have been a hint to Palpatine being thrown down the pit in episode VI.