Like most of the people here, I enjoy chloroform as well.
What I like is to see the victim consciousness going away slowly, through her eyes and body movement. Not to mention the moaning becoming weaker and weaker.
That's way i enjoy knockout gas as well and any other ways that include a slow knockout.

I think a chloroform-soaked cloth is the best just for the massive sexual overtones of it and all the heavy breathing and the heroine that goes limp in somebody's arms. For me the best thing that can happen after any kind of knockout is when the baddy maybe takes hold of the unconscious heroine's chin and tilts her head from side to side. Also any pose or anything that involves her kneck being tilted back, arm carries good for this. That's also another thing that's good about chloroform, as the victim's head is often forced back.

I also really really like it if the heroine has fallen on her front if the villain rolls her limp body over onto her back.

My favorite method of knocking out the heroine is having the villain sneak up behind her and slug her with a blackjack/gun butt/club. This does not mean I don't like the chloroform. That is exciting too. When they get knocked out from behind I like to hear her make a soft groan like: OOOOHHHHH, then fall backward and land on her back.
If she falls forward and lands face down or slightly on her side that is okay too. Then I like to see the villain kneel down and slowly roll her limp form over on her back. I rarely see that happen but it is very erotic and sensuous to me.
I like the arm carry and OTS both about equally. The further he carries her the better such as outside to a waiting car. Carries are more exciting if her arms and legs are swaying to and fro as she is being carried. Some actresses really do this part well and are better at this than others.

If the superheroine has interrupted a burglary and gets knocked out I like to have the burglar continue his burglary with the pretty heroine lying knocked out on the floor and as he continues to open the safe or whatever I like to see him pause and look at her to make sure she is still out cold. Than after he gets the loot he carries it out in a brief case in one hand and the knocked out superheroine over his shoulder with his hands on the back of her legs as he goes out the door to his getaway car parked in the dark alley.

I do like the head ko's for the surprised, "Ohh!" as well. I think one of my favorite things is when the girl moans softly into the chloroform rag though.

And I have to agree, swaying limp limbs is what makes the carry. The removal of the knocked out girl's boots and shoes is a great way to show off the limpness in her legs, too. It's awesome when you see someone holding her with her legs dangling freely while someone unlaces and pulls her shoes or boots off. With every motion, her legs sway a bit, it's unbelievable.

I'm glad this thread is getting so many replies! It's great to hear other people's opinions.

For me, it's what happens after the knockout that's the icing on the cake. When the victim of the KO is carried off, dragged into another room, or tucked away in a closet, or what have you.

For instance, what makes the Fausta scene in the 1970's Wonder Woman show, for me, is not just the knockout itself, but everything that happens after: WW carried into the car unconscious, then carried out when they get to the plane, then the brief but lovely shot of her face resting against the corner of the fuselage before the henchman tucks her head down inside the plane.

Although slow KOs (eg gas or chloroform) can be really sexy, I also think a really quick KO has its own appeal, like the powerful heroine is completely over-powered REALLY quickly.

Also I think someone may have said this already, but any comments the villain makes to the effect that "omg she was pathetic I beat her really easy" are really good, especially with physical KOs like when the heroine loses a punch-up.

this clip is a good example of what I mean:
http://www.youtube.com/watch?v=KAWHdUoqeJ0