I know a lot of people don't like cities built to cram in as many people as possible, but I've spent 2+ years filling (currently) 97 large city tiles, but it amazes me that every one ends up completely different despite that I almost always only use euro style Maxis buildings (and occasionally a few plops for diversity).
So here is AstonVille (original huh). 97 cities allowing 48 million people (more people than there are in Canada) to live in cities with 3 times the population density of Hong Kong.
My largest city Londoninium has a population of 1,051,355 people and.. it's hideous. Most of my cities have between 250k and 500k which allows for some more suburban areas and people not having to live overhanging motorways and factories.
My version of 'surburban living':
Prime apartments overlooking untouched natural grassland, with great connections to Downtown.
Personally the best thing to do in SimCity is cram as many people as possible into a city, then try and fix/improve the problems that comes with it (mostly traffic but also open space, healthcare, education, poverty, etc)
Hope you'll enjoy my journal as I show you some of my experiences with highly populated cities. No mods or cheats and few plopped buildings just natural growth.. (I think..)