I read the first two well before i ever watched the series. It should come as no surprise to those complaining that seasons 1 (and to a lesser degree but still in some ways season 2) are fairly closely tied to the first two books. there are however, some differences in the five novels which could actually have given the show different directions to go in:

-dexter's brother escapes in the novel
-deborah finds out some of what dexter is up to, but doesn't know the full extent
-doakes doesn't die, but his tongue is cut out and he loses limbs as a result of a killer that dexter actually saves him from
-the most interesting one: cody and astor had such a brutal experience from their father that they have their own dark passengers, and dexter mentors them.
-rita doesn't die
-dexter is never as emotional in the book as he is on TV, although it appears that when he has a child in the novel he will become more emotional than ever before

even though he is deluding himself to some degree, dexter in the book is considerably more emotinally detached. i believe that for a TV audience, more work was done to humanize him, which is also why i think the kids as mini dexters was never taken up, even though harrison has shown signs of such behavior since they put him in a similar circumstance as dexter was in, which is OK, but a bit too cliche for my tastes. i'd have much preferred them keeping rita alive and seeing him align more with the kids or her finding out and accepting it. they kind of made her too innocent and naive though to seemingly ever accept dexter as killer of killers, ALTHOUGH the way she liked him punching out the neighbor showed something...

they took a big risk in killing off rita so should be commended for at least trying to keep taking the show place after making such a bold move. the theme throughout every show has been dexter and kindred spirits, as he's come into contact with at least one every season.

i strongly disagree that things are "convenient" or just "fortunate" for him. the criminal justice system is mega fucked up. there is none better to game the system than one inside of it. cases are often so poorly put together and major things overlooked its not beyond the realm of this fictional world for things to break well for him when needed. nevermind the fact that everyone has shown some gray so that alone would seem to indicate that there is no perfectly virtuous soul to go after dexter who hasn't played dirty in the past themselves. aside from the fact that his wife got killed, he has more people pulling on him and depending on him, making his vocation all the harder to accomplish.

whether or not deb finds out about him doesn't have to make or break the show. he says and she shows that she has a "blind spot" for him. and with her finding out about his early days, not hard to see why she lets him get away with being a bit of an oddball.

i'm pretty satisfied with the overall run of the series, they've kept a pretty good hold on the personalities of the main characters. i do think it was lame though that they broke up angel and his chick so he could pound laguerta, unnecessary plot line that they put into the show.

i felt sad for him at the end of season five. for the first time, he was allowed to be himself and while he wasn't judged for it, he also wasn't allowed to have that connection very long. what i do like about the show is that it explores more of his humanity and shows by nature of him NOT killing innocents, and instead going after very guilty parties, he's not the monster harry and he himself suppose him to be.

i could definitely see a "trial" type shit happen, that could be really good if done right.