eldar have got something for everyone, and have lots of combinations, fast bikes or serpent lists or slow durable wraith list, mass guardian formations or elite aspect strike force.
warp spiders are a very strong unit both mobile and with good firepower,
scorpions are one of my favorite units but suffer from a decent way into combat,
fire dragons are just the best at tank busting and character hunting but need a wave serpent to make the most of them.
wraithknight is just all round bad ass but avoid sword option as it dose not give you much.
crimson hunter is very good and more useful than the hemlock.
also don't discount the humble catapult as its blade storm ability can shred terminators on a roll of a 6 to would and you can get a lots of shots out of a squad. combine that with the fact that just about every unit can move in the shooting phase just after or before shooting means even your humble guardians are nasty.
best thing to do is to pick a craftworld you like the look of and build a list around that with the units you like the best.