Music: Best Non-Album Single

Eric extends the B-side discussion to this topic: what is the best song that was only issued on a single, not on an album (apart from compilations)?

He suggests the Led Zeppelin b-side "Hey, Hey What Can I Do" (which Shell mentioned today as the best b-side - although he may have referred to it as "Hey Hey My My").

I'll nominate two Roxy Music singles: their incredible debut "Virginia Plain", and "Pyjamarama".

Have to mention the Smiths - "Ask" and "Panic".

For nostalgia, how about ABBA's "Summer Night City" from 1978?