Surviving a galaxy-wide holocaust is no easy thing. Some of the Jedi on this list survived on their wits, courage, or dumb old luck. Others, like Inquisitor Jerec, took an easier way out. They just became huge dicks along with the rest of the Galactic Empire. Admittedly, it was probably a lot easier than trying to avoid a literally endless army of crack troops in uncharted space.
At first, that's exactly what Jerec did. Accidentally, anyway. Having trained under Jocasta Nu (the Jedi librarian lady from the prequels), the then-benign Jerec started out as an archeologist. When Order 66 kicked off he was safe and sound in the "Unknown Regions," studying Force-sensitive pottery and ancient Wookiee toothbrushes. By the time he got home, the Great Jedi Purge was basically over. Maybe that's why, rather than kill him on sight, the Empire gave Jerec a choice: death, or life as a total asshole.
As was previously mentioned, he chose the latter. He was damn good at it, too. Jerec became an Inquisitor -- hunting down other, less morally malleable survivors -- as well as a Dark Jedi. That's completely different from a Sith, by the way, for reasons so obvious that nobody bothered to actually come up with them. All-in-all, it was a pretty good gig when compared to "certain execution."
Unfortunately for him, he crossed paths with one Kyle Katarn several years before the latter became an utter badass. He did so by killing Kyle's father, which led the hero on a self-taught path to Jedi knighthood, mastery, and eventually the Jedi High Council itself. Jerec had decidedly more evil plans. Namely eating a bunch of Force ghosts to gain the power to switch off suns. Kyle, his inadvertent creation, foiled said plans, and ultimately succeeded where Order 66 had failed many years earlier. Still, Jerec had a good run for a guy that looked like Michael Ironside with a blind makeup artist.
Being a sentient, walking tree, T'ra Saa had some distinct advantages over her Jedi comrades when it came to surviving. Members of her species, the Neti, live for thousands of years. It's unclear whether she made it quite that long or not, but she certainly outlasted the majority of characters on this list (though not all of them).
We know that she was around for quite a while before that, too. T'ra was one of those who oversaw the training of Mace Windu, having become a Jedi Master full centuries before Samuel L. Jackson had even thought of purple lightsabers. Apparently, there was no dumb luck or treachery required in order for her to survive -- she simply evaded the clone troopers of the upcoming Empire without much trouble, along with her fellow Jedi and lover Master Tholme. How that last part worked out between a human and a living willow is anyone's guess.
T'ra managed to sit out the whole rebellion and destruction of the evil empire thing. Apparently hanging out with her comparatively short-lived beau was more important than lending her phenomenal power to right universal imbalance. After Tholme passed on, however, the cosmos were fair game once more. T'ra rejoined the Jedi in the public eye, and even sat on the High Council for about another century. Because watching a millennia-old creature of power and wisdom die of old age isn't that exciting, however, she finally felt guilty enough about not helping Luke, Leia, and the gang. Enough to sacrifice herself for the greater good, at least . In this case, "the greater good" was using the Force to shoot a great big laser at an armada of Sith battleships. Never underestimate a female Groot with the Force on their side.