Jeffrey Skilling served 24 years in jail
Andrew Fastow committed suicide
Ken Lay died of a heart attack before his trial
Lou Pai walked away with $250 million and disappeared
The litany of charges that were brought against the rest of the people involved have not been very successful:
https://www.chicagotribune.com/sns-ap-enron-trial-glance-sto...
All of those sentenced in the above article were for reduced sentences since many of them testified against Skilling and others in order to get a shorter sentence.
The only one who served any real prison time was Skilling.