I guess I forgot to ask, do you feel the "kick" in the pedal at the same time you hear a sound?
Top of the stroke or bottom of the stroke? Both sides?
If the sound comes at the same time each revolution, it's more likely pedals or cranks.
If it skips a revolution, it's more likely chain.

As far as sound, is it still there when you're out of the saddle?
I've got a saddle that creaks, and it drives me nuts.

You may have to throw the bike away, but probably not.