Thomas Perry should be on any list of this sort. I didn’t care for Dead Aim, but otherwise, his books are great.
Sarah Paretsky is good. If you like “whodunnits” then earlier PD James are enjoyable. I found"The Murder Room" disappointing.
I like Dick Francis, but his heroes always seem to be the same self pitying character in each book.
Most of Eric Ambler and Len Deighton.
Both are dated as hell at this point of history, but still very good reads.
I’d suggest starting with the former’s A Coffin for Dimitrios, and SS-GB from the latter.
Enthusiastically seconded.
Everything else he’s written is pretty good, too.
I haven’t read much Connelly, but I really enjoyed The Lincoln Lawyer: top-notch pop fiction.
Maybe the Alex Cross novels of James Patterson?
Even though it’s not exactly “my kind of thing,” I read and quite enjoyed Joe Quirk’s The Ultimate Rush (after reading and loving his very different non-fiction/science/humor book Sperm are from Men, Eggs are from Women).
I can’t vouch for any of them, not having read them, but you may be interested in Stephen King’s picks for 10 Best Books of 2008, some of which are thrillers.
Katherine Neville’s other stuff is also good; I enjoyed *The Magic Circle *quite a bit.
Also, if you haven’t heard, she’s written a sequel to The Eight, called The Fire. It’s not as good as The Eight, but it’s not bad and there are crossover characters.
I like Steve Berry also. Mystic thrillers, very good.
Oh, and you should definitely try The Ruins by Scott Smith.
There’s a book called Thriller: Stories to keep you up all night. It’s edited by James Patterson, and is compromised of thriller short stories from I think 20 different thriller writers. Its a great book by itself, and a great way to sample tons of different authors.
If dated is okay, then I’d also suggest the Adam Hall Quiller novels, featuring a “shadow executive” only known as Quiller. Lots of tradecraft, lots of action, despite the fact that the hero refuses to use a firearm.
I haven’t read that one, to be fair. I never cared for The Phantom of the Opera, so a sequel didn’t really appeal to me.
The Afghan was rather more padding than I was happy with, admittedly, but certainly everything he’s written before that (with the apparent exception of Phantom) is, IMHO, absolutely brilliant. Someone actually used The Dogs of War as a “How-To” guide in trying to overthrow the government of a West African country and very nearly got away with it, interestingly.
I second Quiller. A bit over the top at times, but I particularly enjoy the details of the executives being run by a controller.
I like him, but I find that Cook can get repetitive. As with Dean Coontz, once you’ve read a couple of his books, you’ve read 'em all.
Sorry for the nitpick, but it is either Dean Koontz or Stephen Coonts.
I’m a fan of Dean Koontz (but would not disagree that many of his book are repetitive) and a few years ago I was in the hospital recovering from surgery. My mother asked if she could bring me some books. The pain meds kept me from thinking too straight, so all I could think to ask her to bring me was anything by Koontz. I couldn’t remember the first name nor even how to spell the last. (In the end I couldn’t concentrate enough to read either, but none-the-less.)
She brought me something from Stephen Coonts. They are very different authors.
I love Michael Connelly - he’s an excellent writer and his H. Bosch novels are the best; I heartily recommend any of his books.
I’d also recommend Jeffrey Deaver; one of his main characters is the paralyzed detective Lincoln Rhymes. The Bone Collector, starring Denzel Washington, was one of Deaver’s novels about Rhymes.
I love thrillers; John Sanford is another author I have read and liked for years. I’m always looking for different authors, though, so shall keep an eye on this thread. 
The Reincarnationist is supposed to be very good. I’m looking forward to reading it next, myself. There is also a sequel out.
A non-Rhymes novel by Deaver, A Maiden’s Grave, is fantastic. Hostage situation, deaf hostages, trained FBI negotiator-- well worth reading.
Ferris is my favourite. Isn’t he the one who stamps on cockroaches ?
And Quiller, who kills folks with his bare hands, cringes when he does so.
Good stuff here. Many affirmations of authors I like and many, many good recommendations for new stuff. Thanks again!