I'd really like a seamless service of the Canadian topo maps, similar to ArcGIS Online USA Topographic Maps, http://www.arcgis.com/home/item.html?id=4ee3622f0bfd41eea55ffa83aaf31a9f
If there is no service, is there a download site?
Canadian National Topographic System – Availability of NTS Maps Online
canadadatadownloadmapsweb service
Best Answer
If the main Toporama WMS site is unavailable, www.AlaskaMapped.org has the seamless canadian 250k topos scanned from NTS paper maps under the BDL Extras service (also see here). In the online map browser it's called the SDMI.Topo layer.
Toporama is is more up to date, has better resolution (1:50k) and let's you grab/leave-out certain layers while Alaska Mapped has better performance (and Arcgis layers if you want them).