You can't go wrong with the big names writing today: Mack, George, Bennett, Beyer. The restraints have been lifted now that all the series are over and the authors are free to tell stories on a grand scale that have lasting consequences for the characters and the Star Trek universe overall.
There's a lot of horrible to mediocre Trek fiction out there, but everyone has their favorites that they put head and shoulders above everything else. For me, it's books like The Destiny Trilogy by David Mack, Mission Gamma: Twilight by David R. George III, The Buried Age by Christopher L. Bennett - stuff that breaks the formula.
Laurell K. Hamilton wrote a TNG novel called Nightshade, and she is certainly a hit among the vampire romance (?) fans. They managed to get that one reprinted in TPB last year.