Make sure you guys check out my article about my recent Dark Eldar experiences here. It pretty much sums up everything that have experienced with Dark Eldar so far. In addition, my friend Nick also showcased a lot of his units and what kind of success he's been having with them.
The above list showcases the two playstyles and units that we both found to be effective. Haemonculi (with Venom Blades and Liquidfiers) has been added to the Wych units to give them that much needed FNP. Vect will go with a Wrack squad since they already have FNP. The 10-man squad of Wracks will be quite happy with their 2x Liquidfiers. Things brings me to a total of 4x FNP, full squads with 2 of them being T4. Not bad at all.
My elite choices are filled with 3x 3x Trueborn w/ Blasters in Venoms w/ 2x Splinter Cannons w/ Night Shields. These low-profile stealthy units are fantastic at killing units such as Long Fangs, Hive Guard or any other exposed, meaty unit that's supposed to be anti-tank. By moving 12" with 3 units, I can put out 36 poisoned shots from 36" and hopefully weaken an entire unit of Long Fang's ability to do damage (averaging 3.92 MEQ dead per turn). If I want to, I can also TB these Trueborn into a terrifying anti-armor position for my opponents and then let lose with 3x Blasters each. Truly the flexibility of these units are awesome.
The rest of my list is pretty standard: Vect is there to supply the hurt in melee as well as open up my strategic options. The Ravagers with 3x Dark Lances each gives me a good amount of anti-tank and an opening salvo of 13 Dark Lances. Sure, not the best alpha strike, but still powerful enough to do decent amounts of damage (all 13 will do 7.15 wounds on MEQ and it'll average 3.575 Long Fangs dead in cover). With all my Dark Lances and Splinter Cannons firing, I should be able to signfifcantly weaken a SM's player to wage war with Devastators while maintaining a good amount of cover with everything else.