I repetedly stabbed him in the eye with daggers.
Arrow in the eye. RUN AWAY!
Lightning bolts to the face!
A bunch of well placed traps in the room.
Sword. Screw the impenetrable hide and 20ft height!
I went pure warrior on him. Dash at him, jump attack to the eye. Rinse, repeat until he falls down. Stab him in the eye.
I repetedly stabbed him in the eye with daggers.
One with arrows in the eyes from a safe distance, finished off with a sword to the eye and the other just a sword to the eye three or so times.
1. Climb a rock or similar platform to.
2. Wait for cyclops to get up close.
3. Go into a slashing frenzy with lightning daggers, aiming at the eye.
4. Do a victory dance.
The first time the cyclops was standing in the water. I've casted the lightning spell two times on him (I wasn't even aiming at his eye) and the damned beast dropped dead at my feet.
The second time I've used my sword too, it was a bit harder.
I've done it with arrows or swords, but sometimes it's just not worth the effort. For those times, back up into some convenient architecture and collapse a statue or swing a bundle of logs right onto the sucker. THEN you go for the blade to it's eye
I've got to agree; I particularly liked the last undead cyclops, where we got to smash a big rock on a rope into him, then stab him in the eye.
Mmmm, eye stabbing.
For the one I've faced so far, fireballs to the face and then a dagger in the eye when he keeled over.
Everytime you face a cyclops, there is always a statue or a rock or something that you can hit the cyclops with, which causes him to fall down and be wide open for an eye stab.
First one was with arrows that I set alight using the conveniently located burning garbage pile nearby. Was quite annoyed when I got in the chamber afterwards and realized that you can drop a statue on top of him.
Pretty much the same every time - take ages to kill it and then realize there are awesome traps if I hadn't been too scared to get close.
Spoilers.
The one in the caves - hid behind a rock so he'd get near then eye stab. Is there some way to drop the rail cart on him?
In the temple dropped the statue on him and then eye stabbed.
First one I dropped the statue on. The second one I dropped something else on, I don't remember what it was exactly but it was right inside the entrance. It was literally just walk in, wait for him to run over, whack a pole, stab him in the eye. Kind of anti-climactic, really. The undead one was even less climactic, I found my way up to the balcony and rained arrows on him until he died. Boring, but effective.
I voted "Arrow in the eye. RUN AWAY!", but there wasn't really any running involved. I just found a comfortable, out of reach area, and picked the thing off with arrows, including the killing shot.
It was all a little too easy... :/