My favorite trip was when I took a trip from Washington to southern Arizona via Highway 1 along the coast. The wife (now ex) wanted to plan everything down to the minute, make hotel reservations, plan "shopping" excursions, etc. I told her that we're going to ride until I'm tired of riding, then we'll stop at a coffee shop and fire up the laptop to find a good price on a hotel, then find a good brew pub for dinner. The only thing I let her plan was a couple of days in Disneyland while passing through Los Angeles.
Best trip ever.