You might want to add in a few other variables such as cost of living. I currently live in San Francisco, which in my opinion is the best big city in the USA. SF has a large bike culture, a powerful bike organization that gets results, plenty of public transport, mild weather, and overall is a great city to get around by bike. But it is way too expensive. My second choice would be Denver or Boulder - the cost of living there is a lot better than here but still not cheap. Portland is just too rainy for me, although I have heard lots of good things about it.