This post describes how I exported my 500+ YouTube subscriptions to an OPML
file so that I could import them into my RSS reader. I go into fine detail
about the scripts and tools I used. If you just want to see the end result the
code is in this repository, which describes the steps needed to run it...
This used to be a lot easier, Youtube had an export function to OPML and you could just import it.
Its quite useful being able to follow all your Youtube channels with your RSS reader if you want to pick which you want to watch then also Metube and the browser plug-in makes it a right click and select to send it for download.