For someone who has read all four books of the Night Watch series, I'm not as big of a fan as I probably should be. The series itself focuses on a magician who works in the Night Watch (good), making sure that the opposing forces (bad) adhere to the treaties. In turn, the Day Watch watches the good guys. Of course, this G vs. E construct is not as black and white as it comes across in writing and Anton, the magician, is well aware of this.
While I liked the first book, I think Sergie Lukyaneko has smartly gotten away from the more fantastical elements as the books have moved on, focusing much more on Anton and his growing cynicism and disenchantment. Each book delves into these elements more and I think it makes them stronger as the reader is treated to a very real crises of his soul. To me, the night watch series is a superior example of urban fantasy. It's not always what it seems, oftentimes setting up the supposed good guys as having character issues. Interestingly, the watches are set up more as chaos vs. order than good vs. evil, which allows Sergie to plumb some interesting conflicts. The fourth book is the best, weaving the murky morality of the players with solid action throughout. Sure, it has a few dopey moments, but overall, I really enjoyed this one.