Spartacus is undoubtedly the most famous and best known gladiator in the history of Rome.

He is famous for his role as a leader of the slaves in the Third Servile Revolt, not for his previous career (about which little is known) as a gladiator.

The up to 70,000 slaves who eventually took part in the Third Servile War managed to resist the Romans for two years, before they were defeated and had 6,000 survivors crucified along the Appian Way between Capua and Rome by Crassus (the victorious Roman commander).

Accounting for inflation, the richest athlete of all time was a Roman chariot racer of the 2nd century AD named Gaius Appuleius Diocles. He was in over 4,000 races over his 20+ year career, and won close to 1,500. Records show that over his racing career he earned 35,863,120 sesterces, for that amount you could feed Ancient Rome for a year. Over this period of time, it is estimated that he was paid five times more than highest paid provincial governors of the time. Adjusting for inflation, it is estimated that his career earnings were equal to around $15 billion.

Edit: Source