I traveled a lot by car in the mid 90's, hit just about every state except for about 7 or 8 in the Nothrwest. Personally if i was to do it again I'd still get my old trusty 50 state Rand Mcnally. I don't think anything beats opening up a big newspaper sized map. I know there was parts of Canada in there, at least most of the major routes.
If its pleasure they have just about anything marked you could possibly want to see, right down to the worlds largest hand dug well midway across Kansas on Rt.50 if I remember the right number.
Edit BTW last i checked they could be picked up at Wal-Mart for a few bucks.