Totally gotta ditto this. While I enjoyed books one and two, I was officially hooked with book three and have been a Harry Dresden junkie since. I always PREorder the novels.
Butcher has mad plotting skills, and he's got madder "ratcheting up the stakes" skills, so that once you're in, you're hooked and can't stop, because the complications and complexity of what's going on just keeps sharply rising. It's insane.
It's the novel equivalent of a monster rollercoaster ride with a good friend.
I almost skipped the novels cause I hated the tv show. Boy, did that suck monkey hiney. But a fantasy-writer friend insisted I try it,and he was right. The novels are an amazing urban fantasy ride, with so much action, humor, big-stakes and ever-spiraling tension that if you can set it down and go to sleep, you're a much stronger person than I am.
I found the same effect with SPIN (a sci fi novel) and Ender's Game (also sci-fi) and Neverwhere (fantasy by Neil Gaiman) and The Cemetery Book (also Gaiman). Just had to keep, keep, keep reading.
The Lincoln Rhyme mystery/suspense novels also hooked me bad. I used to get the same "can't put it down" effect from Julie Garwood's historical novels and Anne Stuart's romantic suspense, but I haven't experienced that from those writers in many years.
I have thousands of books in my library, but as I got older, it was harder to keep my attention. So, when a novel does hook me, hurray.