I love the Long-rifle used by Rangers, but I also really like fusion guns and any variation of monofilament weaponry. It's easier to pick a melee weapon I like, Scorpion's Claw, hands down.
Lead. original eldar or space elf pirates were lead. actually so were the first eldar as we know them. og 5 aspect warriors for 10 bucks... them were the days.
Any/all things distortion weapon. Something so deadly that even living Eldar fear to wield it is my kinda weapon! Love the lore for them wraithguard melee weapons as well (powered by soulstones so tortured that they will not be placed back into the infinity circuit as they cause too much unrest among the dead!!), but for melee I'd actually go with the Avenger exarch's dire sword. Because severing souls. >
The Scorpions claw, because it's dead choppy but also , has dakka attached to it so it's also quite shooty.
Mandiblasters, needless to say I was overjoyed to learn that Striking Scorpions are going to be a class in the game. I remember playing DoW2 and being like ''really? Banshees again?''. Other great weapons are the Harlequins kiss, Deathspinner, and Wraithcannon. I still have my old 2nd Edition Eldar Codex. How many times did the phrase ''The target is killed regardless of saves or how many wounds it has'' appear in that book. Anyone remember shrieker ammunition for the Death Jester?
I really love the aesthetics of Eldar power weapons. The swords and spears are simply beautiful. As for ranged weaponry I would say my favourites are the Firepike and the Sunrifle.