One of the parts I enjoy about Brian's framework for the Redwall stories was how he had little mini-stories at the start and end to most of the tales. They make the stories feel like tales told around campfires during winter nights to inspire young beasts to continue the traditions of Redwall Abbey and Salamandastron.
When I first started reading Redwall, I began with Lord Brocktree. What grabbed me initially was that this tale had been compiled by Lord Russano to tell his family, as well as any who came to hear him tell the story. It was a labor of love, with the Badger Lord doing deep research and interviewing the descendents of the battle. It certainly made me interested in learning more about both the story, as well as Lord Russano (though his future appearances are sadly brief).
Compare that to the unique way Brian presented Marlfox. Marlfox was written to be performed as a play to the Abbey for generations to come. You can tell Brian had some experience with writing plays, as it's formed in a similar manner.
I also appreciate that Martin the Warrior features the cast from Mariel of Redwall and The Bellmaker. Mariel and The Bellmaker has perhaps my favorite cast of Abbey beasts, so it's great to see how they were doing in between the two stories. Plus, it's the last we see of Bagg and Runn, the funniest dibbuns in the entire series.
What are your favorites?