I think just about the only composer whose work I don't care for is Hans Zimmer, who is easily the most overrated composer of the last 15 years or so and seems to be most appreciated by listeners who can't discern 'loud' from 'good'. (Apologies if you're a Zimmer fan.)
Well, I think he's a professional and has worked on a variety of films, pretty ballsy. He even tried his hand at a Malick pic years ago that almost killed him due to Malick's working style. I don't know if he's the most inventive, but his work can be effective. (I remember liking the opening battlground waltz in Gladiator, it wasn't quite what I expected to hear; and his ending to Inception mirrored Cobb's restrained anticipation to see his children, etc.) as a musician, I admire someone who can produce consistently and puts himself out there again and again while wrestling with feelings of failure. "Overrated" doesn't necessarily mean he's incompetent or bad, he's just probably overhyped.
I think what Don Davis did with The Matrix -- branding the movies audibly -- should be given more credit, considering it was entirely constructed melodies rather than conventional progressions... basically like doing something in 12-tone, yet everyone recognizes that snippet in the first few seconds.
I tend to like piano work, which Silvestri (in Contact) and Howard do decently with. For a throwaway, Howard's boy's choir piece during the Flatliner credits probably outshined and tonally capped the movie. Howard's typically seen as conventional, I'm sure, but he manages to capture unexpected beauty at times and can adequately support the emotional center of a movie. I don't think the Sixth Sense would have been as powerful without his music shaping and building upon it. I do agree with what you said, [MENTION=5837]93JC[/MENTION], that some of his work is forgettable; but for me personally, some of it endures.
(I also agree with your about Horner, and his resuse of scores. Uggh, some of his music ends up sounding all alike. I like it when I first here it, but then it gets old.)
I was not really a fan of William's in his mainstream years (Star Wars, Indiana Jones, etc.), I kind of looked down on him... and then in the last 15 years or so he has been taking a lot of new chances. I usually bring up the A.I. score, for example. Yes, that was Williams, but it was Williams I had not been exposed to previously. I have a newfound respect for the man.
Gattaca (Nyman) seemed very simplistic but the strings caught the emotional centers of the film at least. And there is an interesting piece written for 6-fingered hands on the piano.
The Cloud Atlas sountrack (Tykwer and Klimek) actually was very important, since the songs written for the movie also had to justify the "intertwined melodies" of the sextet, mirroring the intertwining of the dramatic narratives. It really did capture the grandeur it needed to, in order to justify the movie's own claims about this celestial symphony.
Oh yeah, David Julyan. Now there's a guy who knows how to create atmosphere.
And Michael Giacchino. He's capable in various styles, while also capable of working simply and evocatively to set mood and tone. My first experiences with him were on The Incredibles and with LOST; I don't think LOST would have been such a tearjerker show for many without what he did on it. (I should probably give a nod to X-Files' Mark Snow for kind of setting a trend, but I didn't find Snow as evocative as Giacchino.)
I'm not sure how I feel about Howard Shore. Lord of the Rings didn't do much for me, honestly; however, I like his approach to The Silence of the Lambs a great deal.