Hard to pick one...
Overhyped
Old Faithful
Wall Drug
Coronado Island
Key West
Las Vegas Strip
Door County Wisconsin
Zoos (every single one of them)
Crazy Horse Memorial (if you just stop outside the gate before the pay gate, you've seen it all)
Branson, MO
Disney Parks
Golden Gate Bridge
Alcatraz
Mackinac Island
Fisherman's Wharf SF
Everglades NP
Most caves
Underhyped
Yellowstone NP
Grand Teton NP
Rocky Mountain NP
Grand Canyon Skywalk
Pictured Rocks (and the UP in general)
Legoland (for kids)
Sea World
Soo Locks
Muir Woods
Hoover Dam
Cedar Point Ohio (for kids)