I think nearlights recommendation is for PvP, but sounds like you want PvE advice. pretty much straight damage are your options for PvE if you want to stay as competitive as possible. Fortunately necros have plenty of innate survivability. So that basically means your PvE build will be some variant of 6/6/0/0/2, for max damage potential. Generally the best builds are some variant of power (or hybrid, which I think is gaining popularity as well, and in my personal opinion, is the way necros are meant to be played) because of a few reasons.
Conditions have weird limitations because of the many condition immune objects you will fight, makes it very difficult to take down objects in any group setting, and condition caps in world events make conditions even more difficult to use effectively. Aside from that, there is no optimal condition offensive condition gear. Condition damage only uses one offensive stat, and the only type of gear with condition damage and other straight damage stats is Rampager’s, which has condition damage as a minor stat, not a major one. If there was gear with major condition damage and power/precision, I think it would be a little more viable in PvE since you wouldn’t be gimping your damage with defensive stats while still focusing on your strength.
There are builds further down, I believe the dagger build is optimal DPS but death shroud offers a little more utility.
Personally? This is my pve hybrid build, kitted out with about 60% rampagers, 40% zerker’s gear. I find it really effective, and brings a lot of party utility while still heavy on the damage. I want to test some DPS tonight, actually to see if I’m actually playing horribly wrong or not. I want to play hybrid because necros have a lot of tools that favor a mixed build, IMO. (our main damage trees increase both types of damage, you double dip with might stacking bonuses as it grants both power and condition damage, and there are traits like target the weak and barbed precision which have greater effects with hybrid builds)
With this build, there are some traits that can be moved around, I’m not sure if I like dhuumfire more than close to death, or unyielding blast more than vital persistence, for example. I’m a little underwhelmed by both lingering curse (since I rarely scepter 1, the only benefit is from scepter 2), and withering precision (weakness is underrated IMO, but ~7 seconds of weakness every 20 is a weak grandmaster)