As someone who lived in cities with pretty big variations of sprawl (ranging from Dallas to downtown Tokyo), I feel like density is positively correlated with ease of living.

This obviously depends on your priorities, but being able to walk to the grocery store is a nice experience. I don't have a garden right now, but the public greenery I have access to are usually nicer-kept and I can do 80% of the things I would do in my yard anyways (picnics and the like).

The utility of density is very dependent on lifestyle, obviously, but if you haven't tried spending some time in a really dense area, I'd recommend it. You might find that you won't miss the things you thought you would.

Monocle is as close to a perfect ranking system as I've seen.

http://en.wikipedia.org/wiki/World's_most_liveable_cities

Sprawl struck me as a curious factor too. I can see it both ways - less sprawl means you don't have to go so far out of the city to get into the countryside; more sprawl means there are potentially affordable suburban areas whence you can easily commute into the city.

London, for instance, is pretty sprawling, but many of the commuter towns or villages are actually very pleasant, desirable places to live (they can also be extremely expensive - though not so bad, of course, as central London, which is prohibitively expensive for anyone who isn't an oil sheikh).

I view it differently. Sprawl means you're never where things happen. Everything is somewhere else, and you get there in a car. With dense cities, everything is at your doorstep, and that makes it much more likely that you'll actually participate in great and exciting things and events.

They rated Boston a 5 (worst). Boston is a pretty compact city, and you definitely don't need a car.

You don't need a car for London sprawl - buses or tube are pretty good.

The best kinds of these things are web pages where you can fiddle with the parameters to get your own ranking. For instance, I need sunlight, some warm weather, and places to go outdoors. Others could not care less about that and place much more weight on other things.