I have most of the fights in the series saved to my laptop that I'll rewatch. If I can't find a good video of a certain fight I'll just rewatch the episodes that it happened in. Honestly the series it pretty much training and fighting, there's not a lot else to see. Occasionally there will be a really good episode that I'll rewatch from time to time, such as the episodes with Minato, the Madara flashback, and the episode with Kakashi vs Obito will now be rewatched several several times over well after the series ends.