I have to admit that I like the old stuff better than the new, not because the cops changed, but because in his old age McBain got a lot more kinky.
I agree with Carl Hiaasen and Tim Dorsey. Those guys are really good. I wish more of Tim Dorsey’s books were available as audiobooks. His last two books were, but his latest book isn’t, and none of his earlier books are either. ARGH! Fortunately, every single Carl Hiaasen book is available as an audiobook, so that’s a plus.
Oh, and I like Lawrence Shames too. His stuff is good.
I was introduced to all three of these authors because, like everybody else, I’m a Dave Barry fan, and I read Dave Barry’s two novels, Big Trouble and Tricky Business, and went looking for similar stuff.
Oh, and I recently started reading James Grippando. His book Got the Look was pretty good, although I think it left a few loose ends. Good serial killer book, anyway. I presume his other stuff is good too.
Nobody has yet mentioned James M. Cain (The Postman Always Rings Twice, Double Indemnity, Mildred Pierce)? The man’s genius, especially in the latter, is that while there are legal crimes that occur as part of the plot, the real meat of the story is the dark, self-destructive impulses that drive his characters to commit their crimes even in cognizance of the consequences of their actions.
Jim Thompson is great, too–The Grifters would be a key book in crime fiction literary canon–but I have to agree with jjimm that Highsmith is the pinnicle; at her best she brings the sensibility of a Russian author to crime fiction.
Then there’s Ellen Raskin and The Westing Game, but that’s another kettle of purple waves entirely.
Stranger
My favorite crime novelist is also my favorite author: P. D. James. She’s been writing kick-ass Adam Dalgliesh stories forever, and her few non-Dalgliesh novels have also been very enjoyable – including her autobiography, and I’m not a biography fan.
As for the second part of the OP, I can’t remember where any book I’ve read was set. 
If you like those guy, try this new guy, Marshall Karp. His new (first) novel, The Rabbit Factory is a hoot. Fun plot, engaging main character, snappy dialog and he’s got the whole smart assery thing down, too.
In no particular order, because I’m likely to snap up any book I spy by them that I don’t already have (and a few I already did sigh):
[ul]
[li]Rex Stout[/li][li]Dorothy Sayers[/li][li]Margery Allingham[/li][li]Elizabeth Peters[/li][li]Carol O’Connell[/li][/ul]
John Dickson Carr Locked room mysteries, set in well-detailed not-too-long-ago places.
If I had to pick one guy, I’d say Dennis Lehane. My only problem with him is that he’s not all that prolific, only seven books in the last twelve years. I also read all the Robert Parker Spenser and Jesse Stone books.
Can yoiu recommend any good police procedurals set in today’s LA?
Thomas Harris
Well, this is my favorite genre, so I’ve got a few:
[ul]
[li]Stephen White (Alan Gregory novels)[/li][li]Lillian Jackson Braun (“Cat Who” novels)[/li][li]Jonathan Kellerman (Alex Delaware novels)[/li][li]Agatha Christie (of course, but I’m partial to Poirot)[/li][li]Sara Paretsky (VI Warshawski novels)[/li][/ul]
If you want something a little different, I highly recommend the “Harry Dresden” novels by Jim Butcher. The main character is a wizard…but the books are very “noir” and entertaining.
I’ve recently started reading Janet Evanovich (the Stephanie Plum books, with a number in the title), and have read several of the Carole Nelson Douglas “Midnight Louie” books.
I’m loving this thread, though, it gives me new ideas. 
I can’t believe no one has said, “Ross MacDonald.” All of his stuff is set in L.A., although it’s not all that contemporary.
I’ll second Rex Stout and third Richard Parker.
That does sound different. I’m intrigued.
Wow, I think this is a first for me, somone asking my opinion here at The Dope. Unfortunately, I can’t recommend any. I’m kind of a cotton candy reader, I enjoy it but then it’s gone. Ed McBain had the staying power to stick, though, what with 50+ years of novels.
Georges Simenon with his Maigret stories, mostly set in Paris but there are couple where the police inspector travels to the USA .
To the person who mentioned Ian Rankin and Rebus, have you read any Peter Robinson Inspector Banks books? They are similar to Rankin’s, with a beligerent hero, except these stories are set in the Yorkshire Dales.
Another of my favourites, almost unheard of now, are the Flaxborough books, written by Colin Watson, who died in 1980. These feature Inspector Purbright and are set in the east of England (probably the town of Boston)
What? No Kay Scarpetta fans?
Patricia Cornwell has long been my favorite author, ever since I got interested in forensic pathology.
If Gabriela hasn’t heard of Patricia Cornwell, I’ll slap myself silly. Her scenarios could make movies. One of her books, “potters field” was supposed to have been made into a movie, but I guess it never did.
Ira Levin’s first book “A Kiss Before Dying” is a mystery novel worth finding.
Someone I had forgotten, as yet unmentioned is Thomas H Cook whose books generally have fascinating social backgrounds. The site in the link is terrific for finding good authors in any genre you like.
Bruce Alexander’s Sir John Fielding books are terrific. Not exactly set in contemporary LA, though - he was a real magistrate (brother of author Henry Fielding) in the 19th century, and he was blind. Also another, more recent foray into historical mystery by Roberta Gellis - hers are set in 12th England, and her primary investigotor is a madam. And of course, The Brother Cadfaels.
Other than that, I like what’s known as the ‘cozy English village mystery.’ Miss Marple (Agatha Christy) is a favorite of mine, as is Miss Silver, written about for over thirty years by Patricia Wentworth. I like little old lady detectives and I like the general format - lovely calm village, highly unpleasant person murdered, our hero(ine) strides (Shuffles) in reminding everyone (in the thirties yet!) of times long gone, and solves everything.
I don’t particularly like the books dealing with seedy and sordid crime. I like that setting for some movies - *Blade Runner * did “Chandler in the 23rd century” (yes, I know it was set in 2019, but we won’t get there that soon) LA with all its seedy decadence and I loved it. But not books.