Plug for
Words_of_Darkness for instant 'travel lich' that will last when you zone, in addition to being a solid global cooldown item on its own.
Necro planar wands are actually pretty nice.
Wand_of_Souls is ~1k in instant lifetaps when full, and
Wand_of_Darkness is pretty much just an instant cast epic that you have to recharge.
Staff_of_the_Dreaded_Gaze *is* one of the only ways to reduce the mana cost (increase efficiency) of a fear kiting leveling strategy, but for bigger things like Neze or WW dragons I still find that I have a fear mem'd for when it inevitably breaks early.
Nightshade_Scented_Staff has an (I think?) one-of-a-kind graphic with an Iksar skull? S tier fashion, more-or-less F-tier click.
If you actually play your necro and understand math,
Bone_Bracelet_of_Condemnation is amazing. 500dmg in 15s is 200dmg a tick, stacks on top of all your other dots, and only costs your meditation mana (~40 mana, because you don't have to sit to get lich mana). You aren't going to find ways to use it while tanking like you do with a JBB, but you're a necro and you are probably tap tanking for higher DPS anyway.
The
Manna_Robe paired with soul well and beads allows for a very active form of mana regeneration where you come out about 15 mana/tick ahead for no net loss of hp as Iksar (just costs your sanity, and you don't get the full 20 on average due to the time it takes to cycle beads + soulwell). Pair it with FT8, GoB, PotG, and bard song, and you are hitting 101 mana/tick on your successful robe ticks.
Abashi%27s_Rod_of_Disempowerment was probably not worth the effort and is a symbol of just how badly I wasted the tail end of my 20's, but what's done is done, I love the lore behind it, and it is actually a unique and valuable effect that you can right click from inventory. Abashi was a GM/dev/whatever who played a PvP necro and tried to fight a wizard, who just instantly pumice-stone'd off his dots - and Abashi proceeded to have poison and disease dot mechanics changed so that they cannot be dispeled. [Source: literally just some EQ apocrypha on the internet]. Bottom line is that you never have to 1v1 something that is hasted, sow'd, DS'd, HP or MR buffed ever again and since it only dispels beneficial effects (buffs), your own dots are safe.