I'm an acupuncturist so obviously have had lots. The reason I trained was because it worked so well on my frozen shoulder and I found it so relaxing.
I try and give people as honest an indication on the effectiveness of treatment on a particular condition as possible before they start. However it is not an exact science. Things I would recommend it for almost every time (although if course not 100% works):
Fibromyalgia, shoulder and neck pain, tennis elbow, knee pain, painful periods, sinusitis, migraines, carpal tunnel, Achilles pain, plantar fascitis.
If having IVF so worth it (especially either side of implantation).
Stress, anxiety, insomnia.
Nausea (chemo/morning sickness) alleviating colitis and IBS.
Run a mile from any practitioner claiming it can "cure" cancer, long term tinnitus, hearing loss, sight, genetic conditions etc. Or if they say it is guaranteed. Also if they try and sell Chinese herbs at vast expense. I run a low cost clinic, where we treat a few people at the same time so bring the price down to £15.
Unfortunately many physios have only had a few days of training and almost always when someone says they had acupuncture and hated it was off a physio. Get to a fully qualified acupuncturist if you can (3 years BSc for me). And make sure they are registered with a professional body (British acupuncture association for example).
If anyone wants to know if a specific conditions works well with acupuncture just ask :)