i find this forum more and more drifting towards the existing systems and their pro's and cons. why not imagine we could start from scratch and try to describe how we would do it. let's think boldly : if we were to colonise a planet and had to set up a form of government not linked to any of the existing nation-states, and not a copy-paste of the present constitutions...
wouldn't the first point be the right to live and linked to that the duty to save every fellow human's life (this is not meant to be a statement on abortion or euthanasia, just a legal version of "thou shalt not kill").
as to property ownership : that's the really tricky one : do we need some sort of currency, and how do we fix its value and thereby the value of all our possessions, our work, our time, etc... What have we learnt from the present situation on the consequences of having different currencies, their value decided by political and economical forces and finally also by speculators. in several cities in europe (which has a common currency) there are local currencies popping up again in several european countries (e.g. the "Bristol pound") to offset some of the disadvantages of an international currency and a globalising economy...
another very important point would be the right to (correct) information, which has implications towards education (i agree 200 % with icecreamcon3 on this) but also towards transparency of government, and towards the role of media, and should be linked to the duty and responsibility to also be truthfull ("thou shalt not lie"), because in this issue also the citizens in the present systems are to blame. we are living in a world where a large part of our citizens do not refrain from tax evasion, insurance fraud, etc... - which of course is blamed on the "systems" taking too much, or on the fact that "everybody else does it". still whether it is the "chicken" or the "egg" doesn't really matter, the question is how to avoid this when we start setting up a system from scratch...
several of the points raised in earlier posts regard freedom of one sort or another. i would put these under a general header of the right to live in complete freedom (all equal rights can fall under this) but also the duty/responsibility to respect the freedom of every fellow human being. and this i would base on the principle that one person's freedom ends where another one's freedom begins. i.e. that freedom is not unlimited, by the very fact that we are not one being but a whole species of individual beings. therefore the important thing here is equality ("all men are created/born equal")...
then finally i would very much like some sort of "linking" factor, because after all we are not just all "equal", but we are the same species and we can only survive and pursue some form of happiness if we live "together", we are social beings, so that would need to be addressed as well somewhere along the way...