Generally I hate rope halters, but I do like the Professional's Choice CLINICIAN halter. Very important to get the Clinician style and not their standard cheapo. It comes with a very long yacht rope lead - I think it's like 12' long.
There are different rope materials for rope halters, some are very soft and floppy, some are firm and stiff yet pliable and comfortable, and some are downright horribly stiff and unyielding - impossible to work with. I find the Professional's Choice one to be perfect.
I think I paid $30 for the halter/lead combo. And the lead is NICE! It has a leather popper on the end, and the rope is so soft and flexible. Really great quality.
Honestly, the best rope halter I've had, I got at Southern States for about $5. It is the softest one I've come across, and a bit wider than some-I don't like the super thin ones. It's lasted over a year of daily use and is still very soft. Some of them get very stiff after a while. It has just the two knots on the side of the nose. Some of the thinner, stiffer rope halters are very hard to untie if they get wet or muddy, but this one is easy to manipulate even after my boy rubs his face in the ickiest mud possible. I was expecting to get what i paid for, and to be replacing it often as it stiffened, broke, or got hard and crusty, but it has remained nice and soft.
It's much nicer than the considerably more expensive one I got at smart Pak.
Steele halter if you can find it http://www.fourwinds.net/accessor/steeleh.html. Used by national clinicians-about the best you can get, IMO. This page is just a distributor, he sells to several different places. Bozeman Saddle Outlet in Bozeman, MT has them too.
I have two of these that are going on 10 years old. They are very soft and have excellent feel. I liked the Double Diamond ones until I had to find an alternative for a very soft skinned horse that I had at the time who was getting rub marks. I really, really like the softer rope!
I like the Double Diamond ones... they need to be stiff enough that they won't just drape gently over the face, but not too stiff. It's also important to find one with the lead rope attached, because you don't want to have metal anywhere on a rope halter or in between your hand and the horse. I don't like the knots positioned over the nose, just an ordinary noseband.
The Julie Goodnight halters are actually a very nice weight and balance, I think, if you want a braided noseband. There are a lot of the fancy noseband ones that are really stiff or rough, so you have to be careful if ordering online.
I have a royal blue Arab sized one and love it. I've had it for 3 years now and use it constantly as my main halter. It gets gross and dirty and I just toss it in the washing machine with the saddle pads every couple months and comes out looking brand new. Its soft and small enough that I can ball it up and put it in my pocket or stick it in the small pouch on the front of my saddle. I trail ride a lot and its nice to be able to take the halter with me without it taking up much space.
I also have a rope halter from her that she tied rings into the nose knots to make it into a sidepull. That one is just a chocolate brown color.
The best one may be the one you make yourself. Choose your rope, color and thickness in a hardwarre or sporting goods store. For about five bucks, you'll get enough rope to make three halters. There are numerous methods and directions--google is your friend.
I made one while sitting at my desk last fall and I'd never made one before.
By the by, the fiador was more a headache than I wanted to attempt, so I just did a standard mountain climber's figure 8.
The Steele halters Cowboymom mentioned: I have 5-6 of those and use them almost exclusively. They maintain their exact size (no stretching) and the right sort of 'feel' - if you want a rope halter you can wad up in a ball, they are not for you. If you want one that has a little shape to it w/o sticking out away from the horse's face at odd angles, they are the way to go. I didn't know how to suggest you find them online, so I'm glad she popped in with a link. Mine all came via Cowboymom