Lordy, my list of areas I've cycled in the U.S. is painfully short--just Maryland and a bit of North Carolina when I lived there.

But I've got a respectable list from Europe:
England (as far south as Dover, west to Bristol, north to Durham, east to Norfolk)
Belgium
Holland
Germany (along the Rhine)
France (only where the Rhine touches; pretty much just Strasbourg, which is practically Germany)
Switzerland and Austria (I was going by train mostly through these countries, but used my bike to get around towns)
Italy (Bolzano to Venice, down the coast, over the mountains to Florence and then down to Rome)

Sarah