If you'd asked this last Friday I'd have said another song. Having thought about it since then, that "wankery" made the gig for me. Disagree it was "wankery" mind, the song's about the mess we're making in the world and (imo) the noise at the end was a representation of where Neil thinks we'll end up if we don't do something about it.
It made the gig for me because that's Neil Young in a nutshell, doing what he thinks is the right thing to do and not chasing the popularity the easy way. Did I enjoy the noise musically? Nope, it was shite to listen to. Did I get in the end? Oh yes. Eventually. Do I wish he'd done another song instead. Nope, it summed the man up and the gig would have been much less enjoyable in retrospect if he had.
I said somewhere else that this is one tick done on the bucket list (and it is) but my hope now is that he comes back on his own and, as a bonus tick on the list, I get to see him do an accoustic set. Here's hoping!