Looked at Libertarianism, on the face of it it's quite appealing, but when applied practically to my mind it would appear to offer those who aren't well off a pretty raw deal.
I don't think any one philosophy gets it right though, I think for instance that things like core infrastructure (roads, rail, water, electricity) should be in the hands of government, at the same time though, I think private companies might be better for handling what runs on it, so for instance the government would operate and maintain the track, but itt'd be private enterprise that operated trains, telecoms - government laying the fibre and maintaining the backbone, with phone companies effectively handling billing and last mile issues. At least in that last example, it wouldn't be all that different to how things are now.
I think that not only does the government have a duty to protect it's population (IE armed forces, emergency services) but a duty of care - I believe that whilst people should have the option to choose who provides their healthcare, the government should offer a comprehensive system. Maybe extending Medicare across the board.
I think that as well as a clear separation between church and state, that there should be a clear separation between state and business. Corporate personhood needs to go.
I think the tax system desperately needs to be simplified, so as to stop all the tax dodges that are available at present.
I also think there needs to be an end to private schools being eligible for public funding at the expense of public schools. On education, I think that having a full time independent body responsible for what goes into the curriculum is a must. Perhaps made up of experts in the various subjects. There is simply too much temptation (and I consider this true in both our countries) for politicians to meddle for cheap points at the expense of the students.
Yes, the above is going to up your tax bill, but it will also improve quality of life. I guess it's a tradeoff, like everything else.
I dunno about you, but having the worry in the back of my mind of "will my insurance pay out on this" is not something I'd want on top of everything else.