For North America? Detroit is hands down my favorite. Wide streets, little traffic strong bike culture (think thousands of bikes for “slow roll” or “critical mass”, plenty of cool places to go on bikes, lots of bike manufacturers. I love it. Just don’t’ go to the suburbs (which is a bicycle nightmare).

Montreal gets good votes from me too. Good infrastructure for bikes, just makes it easier than other places.

Europe: Paris is a friggen nightmare any way you look at it. I like the challenge and the dynamics of it, but it is chaotic. Germany has tons of paths isolated from cars and is probably my top vote. And, its not as cold as the highly acclaimed northern countries.