Martyr — Peter David (reread)
Fire on High — Peter David (reread)
I used to read the occasional mainstream Trek novel, but I gave them up a long time ago. I got tired of the penchant most of the authors had for trying to squeeze in as many side characters and references to things that happened in various episodes per page as possible. Plus it's not like anything truly noteworthy can happen in the novels. Franchise canon can be a bitch.
Then several years back the SF Bookclub offered me an omnibus edition of Martyr and Fire on High by Peter David. David is considered one of the better Trek novelists, but the real hook was that these were "New Frontier" novels, a totally new series of books with a new captain, Mackenzie Calhoun, a new ship, and very few ties to any of the TV series. It had been awhile since I first read them, but I remembered them as being better than the average Trek novel.
I hadn't read the first book in the series, though. That one I picked up recently as an e-book, so I read it, and then reread the other two. I suspect that if I had read Star Trek: New Frontier first I never would have bothered with the rest. The book is one long shaggy dog story leading up to a climatic inside joke. And the basic plot was better when it was used in the Next Generation pilot. The other two books are a little better, but nowhere near as good as I remembered.