Well you should pick up Collision Course
. TOS-only books are not usually at the top of my favorites list (since most of the ones from the 70's to the 90's felt like Westerns, and I'm not exactly into Westerns), but Collision was nothing like the TOS books before it. And it really made the Shatner books rebound after the Totality trilogy. It's too bad that Shatner hasn't written its sequel yet.