I was quite partial to some of the Peter David books back in the day, but looking back a lot of them had pretty flimsy plots. He lost his touch a while back though.
Favourite book(s) are probably still a choice between Q-Squared and Imzadi.
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist