what's your favorite bean?

we plan to focus on growing beans next year, as our hugelkulture will need the nitrogen for a year or 2. so we are looking for interesting and tasty beans that we can seed save.
will probably do a teenie bit of the three sisters thing and tuck in a couple melons and squash, but to run and shade out the weeds. suggestions for that welcome also.
xposted in gardening and cooking