Probably several. The Golden Gate in San Francisco is probably the most recognized bridge I've been on but also the bridge in San Diego leading to Coronado Island towering over 200 feet above the harbor. The Chesapeake Bay Bridge and Tunnel connecting Virginia with Maryland and Delaware; the Mackinaw bridge between lower and upper Michigan and the bridge connecting Port Huron, Michigan with Sarnia, Ontario. All of these bridges are very impressive and marvels of construction. On a smaller scale, even the Cedar Street Bridge in Peoria crossing the Illinois River is quite impressive climbing to a height of maybe 100 feet above the river.