Roughly, worklife balance of specialties as a consultant (post training) is as follows:
Somewhat good: GP, anaesthetics, radiology, pathology, dermatology, ophthalmology, rehabilitation medicine, palliative care medicine, endocrinology, rheumatology, psychiatry, neurology, ?sports medicine
Not sure/in between/don't know: ENT surgery, cardiology, gastroenterology, oncology, haematology, nephrology, respiratory medicine, paediatrics, gynaecology, plastic surgery, urology, maxillofacial surgery, orthopaedic surgery, ED, upper GI surgery, breast and endocrine surgery
Somewhat bad: paediatric surgery, colorectal surgery, hepatobiliary surgery, neurosurgery, cardiothoracic surgery, obstetrics, intensive care medicine, pre-hospital medicine
Caveats
- work-life balance as a trainee is different, sometimes better, but usually worse
- doesn't take private vs public into account
- every job is different
- many jobs have on-call (but get called more/less, may/may not have to come into hospital more often)
- you might not actually be able to get a job ie cardiology
There is a guide I used in second year medicine - I think it's called The Ultimate Guide to Choosing Medical Specialties.