lionelflon

The piano concertos are amazing. Number 5 contains some of the most ferocious writing for the piano. I love the jazz influences too - the opening of concerto no. 2 is quite magical (or do I mean 3???). For an amazing but completely un-hummable tune listen to the slow movement of the fifth symphony. The passionate string writing is slightly redolent of JW.

Thanks all! 

And, yes, I was listening to Joe Kraemer's Mission Impossible too earlier. The track "A Flight At The Opera" isn't bad either! As for Giacchino, for some reasons, to me, his music often appears to emulate that of the Masters but ends up being pale in comparison (the only score of his that I can listen to in its entirety is MI3). However, now I think about it, James Newton Howard did some good action cues for King Kong and Vertical Limit. 
 
Also, I should've specified that I wasn't only referring to film music. I remember, a few weeks ago, someone on Facebook, in a group about contemporary music, posted a John Williams' action cue (from Tintin, if memory serves me), asking for a similar type of music. And people came up with some really interesting composers, relatively unknown from the general public, who wrote some pretty dense, visceral orchestral music that somewhat reminds me of John Williams. I wish I had written their name down. Anyway, I shall ask again in that group and report here, if anyone is interested.
 

The biggest problem with today's film music is that there are very few directors with any kind of musical sensibilities. 
It seems like they actively push composers away from any interesting decisions in fear of it being too "manipulative".
Though that's not to say that direct Williams pastiche is the answer either

Some of Michael Giacchino's action music is similar to Williams' modern action style.
 
Also check out Gordy Haab's scores to Star Wars video games
 
Joe Kraemer has some music in The Man Who Killed Hitler and then The Bigfoot that is similar to Attack of the Clones action style

Tons of composers compose in this action style.  The question is what director asks for it.  For example, Ed Shearmur told me personally that no director has ever cared for him to reproduce this "retro" action style he nailed and is fully capable of delivering.  He said he thought this would be his big break into this style of scoring and "the number of times any director cared I wrote this type of score...zero".  There are so many composers who can compose like this but aren't asked to.  The question should be directed to directors for no longer asking for this style.  Anytime it is asked for, it is usually pastiche like "Death of Stalin" which again, Christopher Willis truly nails but that is satire of the Shostakovich/Prokofiev Soviet style which he nails.
 
To answer your question - start first with directors, not composers. 
 

That sounds like JW’s older, more sing song style of action music. Composers can and have reproduced this sound, although JW is still the best. Where JW is really unique though is his modern style, and I still have heard no other composer really come close to that.