In the UK generally most things are free, paid for via National Insurance contributions whilst working.
General practioners - I am very lucky with mine - I can ALWAYS be seen on the day that I call if I need to, they do a late evening surgery and Saturday mornings - bet there aren't many left like that? Often in the UK you cannot book an appointment in advance, so have to call on the day - then if all the appointments have gone by the time you get through on the phone - tough, you have to try again with the same procedure the following day. NOT GOOD! Other surgeries you can call and next available appointment is 10 days away, ridiculous! I am very fortunate with mine!
Some things that are not free to all are:
Dental care (only if on benefits)
Prescriptions for meds ( free to pensioners, under 18's and those with exempt medical conditions ie PERMANENT stomas, diabetes, etc) I just order my ostomy supplies from my GP and collect them from the surgery pharmacy. You can also have them sent direct to yourself after sending the suppliers a prescription form the doc (several ways of doing this I think...) In practice, those with temporary stomas generally will have to pay prescription fees for supplies (unless you can get your GP to sign you up for exemption which often they will apparently). I believe fees for each item on a script are £7.20 at the moment. That would get you a box of 30 pouches I assume.
The cons against this are that if it is not an emergency, then you have to wait - used to be you would wait about 18 months for a new hip! Nowadays things are a little better and their target is to do 18 weeks between referral from the GP to being discharged home after surgery, however, I suspect that doesn't happen in a lot (most!) of cases.
If you have the money, or a job with health benefits then you can get insurance and use private healthcare, same doctors but no waiting, better food and nicer surroundings!
NHS care in hospitals can be a bit patchy according to whereabouts in the country you are - staff are always too busy either writing stuff down, not enough of them (or always on tea breaks - read Johnnotken's funny blogs!) Some hospitals are still in old victorian buildings and seem a bit dirty. Like in anything, you can get good and bad whether or not you have paid for it. Mostly for me it is the waiting that is annoying, not being able to plan anything just in case you might have a hospital date........
I am sure others will jump in with stuff I have neglected to say, but hope that gives you a bit of an idea?
Rach xx