That would eliminate "Waterloo Sunset," which reached #2 in the UK but failed to chart in the States. Still, it may be the greatest song to have not charted here (since it's one of the greatest songs period).

The Byrds' "So You Want to Be a Rock and Roll Star" and "My Back Pages" reached 29 and 30 in the US but failed to chart in the UK.

The one example I can think of that flopped everywhere (if you consider it classic rock) is the next Byrds single, "Wasn't Born to Follow"" (from The Notorious Byrd Brothers), which failed to chart anywhere despite its appearance on the Easy Rider soundtrack.

Fascinating topic (Layla came to my mind when I saw the headline). Thanks for this history.