Quite a bit of talk on various blogs about the old Ace Books line of mysteries. I'm sentimental about them because I'm a geezer but there are only a few of the Ace Originals I can pick up now and find interesting. There was a Peter Rabe Ace, Cut of The Whip. Peter told me that Gold Medal had bounced it so he took it to Ace. I liked it a lot; no idea why GM didn't buy it.
There were three very fine Stephen Marlowe Aces. In fact Turn Left At Murder is a small masterpiece of suspense writing.
In my teens I read every Ace I could find. I know J.M. Flynn isn't highly regarded but he's one writer of Ace Originals I can still read. Bob McKnight always struck me as the road show version of Harry Whittington (Bill Crider made that point first the other night) but his horse racing books were entertaining and believeable. There are a half dozen others who hold up today, too.
I suppose this is heresy to some but I think Ace was most valuable as a reprint line. It was in the Ace format that I discovered Elizabeth Sanxay Holding (whom I've read and reread all my life), Charlotte Armstrong, Dana Lyons, Stephen Ransome (Frederick C. Davis, a reliable pulpster who occasionally wrote way above his talent), Helen Neilsen. They did some nice editions of Cornell Woolrich as well.
I think the science fiction line did a litle better by way of originals. The early and best work of Samuel R. Delaney was all Ace. That alone justified the line's existence. Poul Anderson, Margaret St. Clair, Wilson Tucker and a number of solid Brits made just about every month a treat. They also published poor Robert Moore Williams, a holdover from the worst of the pulp days. When I started reading him he got trashed by reviewers every time out. By the end of his Ace run I'm pretty sure that reviewers felt so sorry for him they strained to say something nice about his stuff. I always felt sorry for him, anyway. But I couldn't read him. He got even worse when he switched to Lancer. Do you really need to read a book titled Zanthar At World's End to know how bad it's going to be?