With respect to community decisions, the one that has proven to work well is based on consensus. Here's one definition from wiki:
As a decision-making process, consensus decision-making aims to be:
Inclusive: As many stakeholders as possible should be involved in the consensus decision-making process.
Participatory: The consensus process should actively solicit the input and participation of all decision-makers.[1]
Cooperative: Participants in an effective consensus process should strive to reach the best possible decision for the group and all of its members, rather than opt to pursue a majority opinion, potentially to the detriment of a minority.[1]
Egalitarian: All members of a consensus decision-making body should be afforded, as much as possible, equal input into the process. All members have the opportunity to present, amend and veto or "block" proposals.
Solution-oriented: An effective consensus decision-making body strives to emphasize common agreement over differences and reach effective decisions using compromise and other techniques to avoid or resolve mutually-exclusive positions within the group.
Most Logical*: This happens when a solution appears to be impossible to execute because of the lack of support and cooperation.[2]
more info at link:
http://en.wikipedia.org/wiki/Consensus_decision-making
There is also books written on it, that can apply to large community networks called: We the People, A Guide to Sociocratic Principles, by John Buck.
/NS