If y'all use strava, you might find this site:
Strava Multiple Ride Mapper Make sure you just select "ride" under activity types or it will put any virtual rides on the map, along with any other walks or activities you do.
It's like a heatmap of sorts that puts all your rides onto a map and you can see where you haven't ridden yet. You can just select a certain time period too, and download a klm file to do other things with it... pretty sweet little site.