I recently had to evaluate pros and cons about moving from Italy to another country, and I ended up compiling the following table:
Obviously the table is very subjective, so I have to explain some items and cite some sources.
The Metric System is used in Europe, but even if both Ireland and the UK switched to this system, it seems that you can live in Ireland using it only, but that in the UK and Canada the Imperial Units are still in widespread use. Furthermore, in the States you will have to learn the Customary System...
This is a map of the world with RHD (Right-Hand Drive) countries and LHD (Left-Hand Drive) contries in different colors:
About quakes, I've been talking about seismic risk in a previous post; now I just want to make clear that I'm marking the States as "dangerous" since the only State I could relocate to is California, that is known to be waiting for the Big One.
About queens and kings someone could argue that they are way better than some prime minister, but I decided to include this row anyway...
About guns and rifles freely available at the grocery shops (Tesco or Wal-Mart or your preferred ones) it's easy to understand that I do not agree (at all) with this degree of freedom.
And finally, I listed the countries officially taking part in the invasion of Iraq in 2003 (as you can see, officially Spain has been present for some months and Canada is absent).
This post has no conclusion: I could only note that the countries with the best non-weighted scores are France and Ireland.