So after the final battle, lots of people die.
But not everyone! Even people from the bad side had to have survived.
So who did?
It is hard to know which Death Eaters survived because we do not know all their names. Many of the deaths, specifically in the Battle of Hogwarts, are anonymous. We can possibly extrapolate notable survivors with a list of Death Eaters who were killed.
One will notice that Voldemort's and the Death Eaters' kill count is way higher than the Harry/Dumbledore/Order of the Phoenix's. However, that would be expected since we have a classic "good vs. evil" story.
Many other families to be known Death Eaters (and first names not always known) and were not to be shown killed outright.
The Malfoy Family: Lucius, Narcissa, and Draco were seen fleeing the Battle of Hogwarts.
The Carrows: Alceto and Amycus were tied-up in the Ravenclaw Tower prior to the Battle of Hogwarts.
Antonin Dolohov: Was defeated but not killed by Professor Flitwich during the Battle of Hogwarts.
Augustus Rookwood: Sent to Azkaban after the Department of Mysteries incident, but escaped during mass break out.
Walden Macnair: Hagrid slammed him into a wall during the Battle of Hogwarts, but he was only knocked unconscious.
Prior to the Battle of Hogwarts:
Evan Rosier: killed while resisting capture before Lord Voldemort's downfall by Alastor Moody (mentioned in GoF)
Wilkes: killed while resisting capture before Lord Voldemort's downfall by Aurors (mentioned in GoF)
Gibbon: killed by a stray Killing Curse cast by Thorfinn Rowle (HBP)
Regulus Black (reformed): Killed while attempting to destroy the locket Horcrux. (mentioned in DH)
Barty Crouch Jr.: Soul removed by a Dementor (GoF)
Igor Karkaroff: Killed by Voldemort for abandoning the cause.
Peter Pettigrew: Killed by his own magical prosthetic hand, thus Lord Voldemort, indirectly. (DH)
"Several Death Eaters": They were not named. All killed during Voldemort's fit of rage after being informed that Helga Hufflepuff's Cup, which was one of his Horcruxes was stolen. (DH)
During the Battle of Hogwarts:
Scabior: Killed by Neville Longbottom with a collapsing bridge.
Vincent Crabbe: Killed by his overactive Fiendfyre.
Severus Snape (reformed): Killed by Nagini/Voldemort for control of the Elder Wand.
Nagini (animal): Killed by Neville Longbottom with the Sword of Gryffindor.
Bellatrix Lestrange, nee Black: Killed by Molly Weasley with an unspecified curse.
Voldemort: Killed by his own rebounding curse (or Harry Potter from a "certain point of view").