I feel the same way. Those two guys really knew how to tell a story, without all the "fluff".
I like Ken Follett too.. but, he gets a little flaky sometimes. I've also enjoyed a number of Baldacci's books... even though he's gone liberal as of late.
Haven't read much Elmore. Where would you suggest I start with him?
If you like him, I probably will. :-)
Leonard's novels are stand-alone, even in the few which share characters, so it really doesn't matter where you start.
You'll find his writing much leaner and down-to-earth than Crichton's or Flynn's. Leonard doesn't spend much time on descriptions; his forte is characterization through dialog. If you like Hemingway you'll like Leonard.
I first started reading Leonard after watching the film 3:10 to Yuma, which was based upon one of Leonard's short story westerns. A LOT of his stories have been made into movies and TV shows.
I'd have to say that my favorite is novel of his is Out of Sight.