Here's a map I created, using
mapchart.net, of the places in the United States and Canada that I've visited (click on the map to enlarge). It's color-coded according to
how long I spent in each place. The two orange places are so tiny that I'll specify: I've driven through Rhode Island on I-95, and I've only been to the airport in Charlotte Amalie in the Virgin Islands. The rest are pretty self-explanatory—except to say that, though I've probably only spent a total of four or five nights in West Virginia, I've spent enough days and evenings there to amount to several weeks.
I think one nice road trip could easily take care of six of the remaining states and three of the provinces. But of all the places I haven't been in North America, my top two travel goals would be an Alaska cruise and a road trip to Nova Scotia and Prince Edward Island.