The Lord of the Rings movies absolutely, positively trounce Tolkien's work as entertainment. They are more tightly edited and the actors add warmth to Tolkien's unnaturally formal dialogue that just isn't present in a reading, no matter how vivid your imagination is. I think a lot of people give their personal vision of a work too much credit in that regard. I sure as hell didn't imagine half the gorgeous vistas in that film, nor plot out the battles half as meticulously as Jackson did, and I don't consider myself a disengaged reader.
I think the banal distaste towards adaptation mostly comes from viewing a work in a very shallow way - i.e. that the biggest thing you are getting out of it is the plot, as though reading the book were nothing more than a very detailed Wikipedia entry. The showrunners already took a few characters in interesting and new directions (a very mild spoiler follows) such as Cersei's talk to Robert about their marriage, which does more in the space of a few minutes to make Cersei into a human woman than all her chapters in the novels, where she comes off as an absolutely unhinged sociopathic monster.