Much of the material on this web site discusses the advantages of proportional representation voting versus the single-member district plurality voting system. Viewing the choice in these "either/or" terms is useful because single-member plurality voting is the predominant system used for legislative elections in this country and proportional representation is usually considered the main alternative to this kind of plurality voting.
However, the actual range of available voting systems is much more extensive than this. For one thing, there are several other kinds of winner-take-all voting systems besides single-member district plurality. Several forms of PR exist as well. And there are other voting systems that fit into neither of these categories. So you might find it useful to take a brief look here at the full variety of voting systems, if only to put the discussion of PR and plurality systems into a larger context.
There are three basic "families" of voting systems: plurality/majority, proportional representation, and semiproportional. All the voting systems within a particular family tend to produce the same kind of political results and tend to resemble each other in terms of their general political advantages and disadvantages. The main political differences are therefore between the families, not within them. The links below will take you to descriptions of specific voting systems, including sample ballots.
Plurality/majority systems. These are the winner-take-all systems that are usually used in the United States. They include the common plurality systems like the single-member district plurality vote and at large voting, and less common majority systems like the two-round runoff and the instant run-off.
Proportional representation systems. These voting systems are used by most other advanced Western democracies and are designed to ensure that parties are represented proportionally in the legislature. They include party list systems, mixed-member proportional, and the single transferable vote.
Semiproportional systems. Though relative rare worldwide, these systems have garnered some interest in the United State. They tend to produce more proportional results than plurality/majority systems, but less proportional results than fully proportional systems. They include cumulative voting and limited voting.
(The descriptions of voting systems that you will find here are brief, but should be adequate to give you an idea of how they work, and at least some of their general political attributes. More detailed information on the operation of these systems and their political consequences can be found in Behind the Ballot Box: A Citizen’s Guide to Voting Systems. Also, if you are interested in seeing which countries around the world use these various voting systems, you can visit a web site that shows this information either in table form or in map form.)