The best I've seen is Topo (by Nat'l Geographic). It has much more detail (7 CDs for WA state) than my Garmin maps (2 CDs for the entire lower 48). It uses the USGS 7.5 minute maps which show trails, FS roads and usually a 40' contour interval. Topo imports & saves GPS tracks or can create / export waypoints back to the GPS unit.
It also allows you to print your own maps (with or without tracks) which is handy for new areas or boondocking expeditions.
Reg price is $100, I've seen on sale for $75. Might do better on-line or Ebay.
There are a number of sites that have downloadable snowmobile area Topo maps created for WA (numbskull.com, wssa.us, etc).
I found a sweet program called expertGPS to take old tracks and cut condense merge rename and otherwise clean them up and sketch out new tracks to go explore the next time I am out. It has USGS satellite maps and topo maps built in so you can draw tracks right over aerial imagery. I still use google maps satellite images for more up to date views to make sure what I am sketching will possibly work but the usgs maps work pretty good for what I do. it uploads to and from your device, but you will still need your mapsource program to load the base maps if you have a Garmin handheld unit, I haven't figured a way to take gps maps and display them and use them but maybe you can find the way.