I’ve been hearing about Lawrence Block’s crime fiction since forever, but I finally got around to reading some. Now I wish I’d done it decades ago.

This isn’t my copy, but is the edition I read.
This first thing of his I read was The Thief Who Couldn’t Sleep. I didn’t believe in the hero, Evan Tanner (who suffered a traumatic brain injury in the Korean War and consequently never sleeps, but suffers no apparent ill effects from this) or the crazy adventures he got into in and beyond Europe in the frosty depths of the Cold War. But it was a fast-moving and fun adventure, and all the sex in it is friendly and consensual (not always the case in these things).
The weakest and dullest part of the book was the very end, where our unlikely hero becomes an operative for an even more unlikely super-secret spy agency. But that’s forgiveable as a set-up for the ensuing series (which carried on for a dozen or so volumes).
I’m currently working on the first novel in another long-running series by Block, Burglars Can’t Be Choosers, and his collected stories (under the title Enough Rope). I can recommend both on the so-far-so-good principle.