I very strongly urge an adoption of Instant Runoff Voting-Single Transferable Vote (similar to the method used to elect the President of Ireland).
If we're not careful, then we'll get into big religious wars about what is the best method of voting in this situation. Many people think that IRV is unnecessarily complex, while agreeing that FPTP is still indefensibly simple.
Although I'm personally a big fan of transferable vote systems, if we really want to get a clear consensus to do away with FPTP, then it may be best if all of the FPTP opponents agree up front that any voting system chosen from instant runoff, approval voting, and Condorcet (with any specified method for resolving Condorcet ties) is an acceptable, consensus-building voting system, while FPTP is not.
-- Toby