Darth Formant - He was always providing the Jedi with tips about Sith activities.
Darth Active - Spent most of his time on the couch with Darth Ternet.
Darth Corporate - Copied the schtick of a lot of other Sith.
Darth Corrigible - He never returned to the Light Side.
Darth Competant - The Emporer had this idea about letting Stormtroopers become Sith...
Darth Destructible - The only Sith to ever get to roll d100's for Hit Dice.
Darth Grown - Spent most of his time at the podiatrist.
Darth Come - Because someone had to pay for all the nifty Sith toys.
Darth Spection - Was always checking that the other Sith polished their boots, made their beds, and kept their lightsabers in working order.
Darth Struction - Although a mere apprentice, he liked to give orders.
Darth Strument Panel - Was only ever appreciated by the other Sith during flights.
Darth Solvent - Joined the Sith in the hope of paying off his credit cards.
Darth Nate - He was born with fully developed Sith abilities and never needed a day of training.
Darth Possible - Slept through Sith Names 101 and thought it was okay to choose a word that starts with "im". Shared his notes with others, resulting in Darth Perfect, Darth Portant, Darth Pale, and Darth Maculate having to choose new names.
Darth YPD Blue - Bared his butt more often than the other Sith.
Darth Staller - The Sith assigned to set up the appliances on Sith vessels.
Darth Filtrate - The best spy the Sith ever produced.
Darth Itials - Everyone called him "D.I."
Darth Terminate - He just keeps going on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and on and....
Darth Exterminate! - The Dalek Sith who saved the other Sith from death by boredom at the hands of Darth Terminate.
Darth Determinate - Nobody really knows what he is.
Uhhh... I'm gonna stop now while I still (barely) can.