Balthamel/Aran'gar is my favorite. I love the physical description of Balthamel when he is released from his spot too close to the surface of the Bore where time was able to wear away his body to the point of such deterioration that he covered himself from head to foot, and gave himself a maliciously grinning mask. CREEPY AWESOME! Plus, death by fungus was new to me.

Aran'gar is awesome because it's a soul of a man in the body of a woman. There's a perversion there that the forsaken embraced whole-heartedly. Promiscuity oozed from Halima. Plus she one-upped Moghedien by freeing her, freaking her out in the process using sadin. Then she positions herself brilliantly with Egwene putting her in the best place to cause chaos and break the rebel Aes Sedi.

Creeper, devious, and evil. Balthamel/Aran'gar rocks.

I think I have to vote for Demandred, simply because he seems to be the only one of them that hasn't yet screwed up royally and gotten him/herself killed, captured, punished by the Great Lord, etc. And for the mystery.

I like Demandred too. He's such a secret, no one really knows where he is or what he is up to. He's gonna cause some trouble yet and it'll be fun to finally find out how.

Ishamael/Moridin. The Forsaken are all made out to be super smart and dangerous, but I get the feeling he's the only one who truly understands the nature and plans of their Master.

Demandred would have been my choice simply based off the mystery factor. He is totally the dark horse, because we simply have not seen the man do hardly anything throughout the series. But because he is cloaked in so much friggin mystery all the time, and always behind the scenes doing his.. Well, see my point? He may have been sitting in a palace with his feet kicked up the entire ten books or whatever that he has been free for all I know! So, I'll go with the only one smart enough to know that if they win, they all cease to exist, rather than being raised as "lesser gods", under a supreme god and his choice pet of the moment who sits higher than they do. So, Ishamael/Moridin for me.

the one and only,the amazing lanfear.

in my opinion,robert jordan biggest mistake(story wise) was to remove both

moiraine and lanfear at the same time,it created an enormous void.

so two books later we got the grandmother from hell cadsuane,and a book after that the two-dimensional insignificant character cyndane.

part of what made lanfear so attractive were her many interactions with rand,it created a very tense(to say the least) dance between a dragon and a very unpredictable cobra,and because of that,every time rand and lanfear were together sparks flew lol.

regarding cyndane,rand never even knew she existed until the end of tom.

i must agree with jack... lanfear by FAR is the most interesting forsaken...

and, moraine and lanfear have had nearly identical parts to play... moraine leading rand to the light, lanfear to the shadow...

lanfear is the one with the most depth... she's veyr powerful, the one who first drilled the bore, obsessed over rand to the point of insanity(related to the drilling?), and yet, she's one of the few i could see returning to the light...

For me it's Ishamael/Moridin. He seems to be the most philosophical of the bunch.

I'd have to go with Ishamael/Moridin. He's unique in that he's the only one of the Forsaken who isn't just out for immortality and personal power. In a way he's a tragic figure who just wants it all to end. He sees the world as pointless and just wants to finally have peace (although the peace of oblivion). I'm not saying I agree with him of course, it's just that his motives are unique among the Forsaken and that makes him the most interesting IMHO.

I have been a great admirer of Semirhage ever since the brilliantly written torture scene of Cabriana Mecandes and het warder. The simple idea of murdering someone by activating their pleasure centers instead of inflicting pain on them, is a very unique trait for a "bad guy/girl". But the reason I like Semirhage the most is probably because of Seamas's drawing of her. Only upon seeing it did I realise how much her looks and ways differ from those of a generic fantasy villain.

My vote is for Moridin. I reread his POVs not once. He is treacherous, smart, and his motivation has strong philosophical foundation. A bit mad, though, but I never mind. :)

I am still very new into the series (I just started The Great Hunt), so the only Forsaken I have been exposed to are Aginor and Balthamel. So from lack of other options I would have to go with them.

Lanfear. She went from haughty to pleading for help. Maybe she'll be rescued, and turn to the light in AMOL. Can't wait to read the last book!

Demandred, because he is very calm and calculated, though he obviously pushed himself to a complete breaking point through years of envy. Perhaps he will snap again, out of envy of Moridin, and perhaps assist Fain before being destroyed by the DO?

Lanfear! Beautiful, powerful and crazy. Exactly how I like women! ;)

Ishamael/Moriden - the rest are all like fighting childern.

Honestly I love the idea that evil can be changed to good since everyone has some good in them and Jordan allows that to show through. My pick is Asmodean!

mine is lanfear because even though she may have played nice throughout the books i've read; she still killed M. (M is because of spoiler). Therefore she is a double agent, which makes the books much cooler to read.

Lanfear

Ishamael/Moriden He seems the most sensible one 

i like Moriden the best. not Ishmael... Moriden. I like that now he seems much more thoughtful, quietly commanding, and just plain more scary to the other forsaken. He dominates by sheer presence instead of yelling demanding and otherwise bullying the others. now he just needs to stair at them to cow them

Demandred

Semirhage, a fantastic evil being that it is immense fun to read about.

Graendal. She's seriously twisted.

Ishamael/Moriden, Its going to be interesting to see how his connection to Rand effects the last battle.