Which is the best type of chimney flue liner
The best type of chimney flue liner depends on many factors, including the type of appliance, the type of chimney, and its intended use. Not to mention, who's answering the question!
If you are planning to have a new chimney built, or considering having your chimney re-lined, get as much information as possible about the appliances you will be using on that chimney. Check the owner's manual to see if there are specific recommendations for or against certain types of chimneys or liners. Talk to the experts at your local stove shop, and talk to your chimney professional.
Don't assume that any old chimney flue liner is fine, or that the brick mason knows what type of liner is the best.
I do not mean to be critical of masons, their work is certainly important, and a good mason is a true artist. But with new wood-burning technology has come the need for new types of liners; and if you don't ask the people on the front lines, the ones who deal with the issue of selling theses appliances and making happy customers, you might end up with a chimney flue liner that is totally inadequate for your needs even though it might be a doggoned well-built one!
Current construction and safety standards require that all chimneys be lined. So if you think your chimney is unlined, or you are not sure, have your chimney checked by a chimney professional, and ask him/her what types of liners are appropriate for installation in your chimney.