Game Plan by Randy Delelles and Jeff Kriske
I have all 6 grade levels of Game Plan and they are an amazing resource. There are tons of songs, games, visuals, etc.. What I really love is this series helped me better spiral my curriculum. I am much more aware of the direction I'm heading in with lesson planning and I believe this has greatly impacted my students musicianship.
Mallet Madness by Artie Almeida
Artie is awesome! I love many of her publications but Mallet Madness is one of my Go To's. This is such a great resource for incorporating children's literature, mallet technique, and more.
The Orff Source by Denise Gagne
I love this resource because it is sequenced by tone set (sm-lsm-etc.) it is great to quickly find a song to support your objective.
While there are many other resources, including my Level binders, that I own and use these 3 are the ones I find myself going to first.