Route info needed...

I'm meeting my brother in Idaho next month. It will be my first long trip in the new GS.

The Navigator II and Mapsource say I should slab it through Reno and across western Idaho till I arrive at destination.

Are there any "must see" roads or attractions? I have 5 days for the round trip so I can't do justice to the American West, but I'd like to get off the highway for something worthwhile.

/taking recommendations