I'm growing 24 kinds of pole beans this year (in addition to a lot of runners)
The most productive is Blauhilde, a purple German heirloom from Baker Creek. I've been picking them a couple of times a day as they seem to elongate as I'm watching. Taste good, too. Apparently they are tolerant to mosaic virus, but I don't know what that is.
Victoria, British Columbia, Canada a cool mediterranean climate - rainy winter, dry summer