I just finished Lawrence Block's A Stab in the Dark, which is one of his Matthew Scudder books. This is actually the first fiction I've ever read by Block, and I see what I've been missing. Nice tight writing and a well told tale. I'm definitely going to be looking for more of these. This one was published in 1981. Probably the main reason I've not read him before is that I'm not typically big into mysteries.
The first thing I read by Block was Telling Lies for Fun & Profit, his nonfiction book on writing. This was excellent, and from there I decided to try his fiction. I got A Stab in the Dark at a book sale, but I'll be checking his stuff out next time I'm in Borders or Barnes & Noble.
I certainly recommend the two books of his I've read so far.