Dark Side Jedi

Dark Side jedi's are the ultimate PvP class. They dominate the battle field. Here is where you will gain great power over your opponents.

I will first recommend gettting done with the Cloak Collection and getting all those holocrons.
3 types Armor/Mods you can use.
1st Elder Robes give high stat rating for 3 stats and good Armor Rating.
2nd Using traditional Armor that has been Modded. Ever since the update came out where jedi can use Armor this has been very popular to those who have not completed the jedi collection or who are not elders.
3rd Collection Cloaks giving stat increase to all stats and very nice Armor Rating as well as either lightning damage increase or lightsaber damage increase.

Dark Side Jedi
Now dark side jedi's are made for pure offensive ability. The opposite of the light side jedi. Although dark side jedi's can be used to be very good tanks and still dish out heavy damage I always perfer to increase the given skill to overpower my opponents. I will of course do two side a well balanced and a pure offensive dark side jedi.
Glass Cannon (PvP):
Now this like most have said is a Glass Cannon very one sided build pure offensive ability at the cost of defense. I personally love this build and if you know how to play it then the defense factor doesn't really make a difference. As for the basic mod's you will need Agi, Luck, Pre. Those should increase there offensive ability while adding a base of defense from the Agility. Exotics should be as follows PvP Critical Chance, Critical Hit Chance Increase, Glancing Blow Range. That should go to shirt, lightsaber, and chest if you use armors. The PuP's (Power Up's) should be x3 PvP Crit Chance. Entertainer buff I always go with 3K kin/eng Armors, Crit Chance, GB, 60 Pre. This should be used with Gackle Bat familiar for the added pre, and str. I always use Breath of Heaven for food and is the best universal food for most professions. I like it on this build for added health. A good Breath of Heaven should be 200+ Constitution. Heroic Jewelry for this build for this build should of course be Dark Fury. That gives you a chance to reset the Cooldown on an attack, but most importantly it gives you the ability to reduce the overall cooldown of all your lightning attacks giving you more damage and more chances to crit.

Balanced Dark Side Jedi (PvP and PvE):
This is actually well balanced and you take off some of the pure offensive abilities and switch them for defensive to balance out the profession. I suggest as basic mod's either 1) BV, Str, Agil 2) Agil, Pre, Luck. Exotics for 1) would be Block Chance, Glance Blow Range, Block Value and 2) would be Glance Blow Range, Agil, Critical Hit Chance Increase. The Aurilian Jewelry for 1) Is the Guardian Set and for 2) Heroism Set. This set it's best to add as much Agil as possible and get food with +150 Agil. If you choose to go with the Block build of 1) then go with Fizz pudding for the 3% Block Chance and added luck. I would choose the Mynock or this build because here your trying to increase the agility value as high as possible. As for the expertise I would use the same one since that one works best for whichever dark side jedi you choose to be.