Glad to see that one person (though only one so far!) submitted "October Song" by Robin Williamson of the Incredible String Band (on their 1st, 1966, album). This gets my vote not just for being the best Octobe song but the best song of all time (and I don't just say this because I was born in October). Mind you, though fortunately I haven't heard anyone do a cover version of it I think it would be very disappointing by comparison, as I don't think they could emulate Robin's voice and guitar playing.