I've been using Delorme Topo for a few years. No great complaints with the product. The only drawback is that it doesn't differentiate between paved and unpaved roads (there are plenty in our area), so you need some familiarity with the route. And it has ride profile capability, which is a major plus.

www.topozone.com is an online resource for topo maps. Not as good as a ride profile, but it gives you some idea of what kind of terrain you'll be dealing with.