Requiring insurance companies to insure people with pre-existing conditions is a good thing, as far as I'm concerned. Allowing people to stay on their parents' insurance until they are twenty-six is a good thing, too. Requiring a certain percentage of premiums to go to patient care is a good thing. Removing the cap for how much care insurance companies will cover is a good thing. Making preventative care free is a good thing. I consider those things improvements over how things were before ACA. I also think encouraging providers to use electronic medical records is a good thing.
Edit: If you are in favor of a Singapore style system (which isn't my first choice, but is better than pre-ACA and probably better than ACA), campaign finance reform and closing the public/private sector revolving door would be really good places to apply your effort, IMO.