Hey guys I have question

I'm preparing a vacation not anytime soon but in 5 years I have travel plans to go the USA with my motor bike and cross the USA, the plans are to travel from the west coast to the east coast with friends on a motor cycle were planning to take 3 months off maybe longer for this.

I would like to know if you guys have any suggestions what there is to see because were not looking for too much mainstream hotspots but more the little gems hidden in that big country to visit.

Thanks