Even Michael gets in the occasional good one, like when they find the ticket agent praying during the hob attack at Union Station:
The white fire of the holy sword painted the tear streaks on her face silver as her mouth dropped open in an expression of shock and stunned joy. She looked down at her crucifix, and back up at him again.
Michael took a quick glance around the room, smiled at the woman, and said, “Of course He’s there. Of course He listens.” He paused, then admitted, “Granted, He doesn’t always answer quite this quickly.”
A good example of Harry's wit is Murphy's speech (and Harry's response) about how the clandestine, supernatural meeting would not happen without her present.
Made even funnier by the fact he's saying it to a Valkyrie.
Later, Harry is meeting the Archive at the aquarium:
A pair of dolphins swept by us in the water, flicking their heads to get a good look at us as they went. One of them made a chittering sound that wasn't very melodic. The other twitched its tail and splashed a little water our way, all in good fun. They weren't the attractive Flipper kind of dolphins. They were regular dolphins that aren't as pretty and don't get cast on television. Maybe they just refused to sell out and see a plastic surgeon. I held a fist up to them. Represent.
The dolphins later help Harry against the villains, having apparently decided that he's the good guy.
Eldest Brother Gruff: Likest thou jelly within thy donut? Harry: Nay, but with sprinkles 'pon it, and frosting of white.
A boon from the Faerie Court of Summer, to use for any one thing he saw fit, and he uses it for... a small favor.
And later, when he finds the donut in his car, still hot, Thomas asks him "Where did that come from?" He just smiles and keeps eating.
Thomas: You don't even explain the little things, do you? Harry:It's like a drug.
For that matter, Eldest Gruff's arrival.
Thump. Thump. Thump. I adjusted the aim on the staff a little higher. Thump. Thump. Sweat trickled off my brow. Thump. Thump. How far did this guy have to walk? Thump. Thump. This was just getting ridiculous, now. Thump. Thump. And Eldest Gruff appeared in the opening. He was five feet tall. Five-two, tops.
Harry's reaction to watching Kincaid click off his gun's safety and lay it across his chest before going to sleep.
Harry: How cute. He's got a teddy Glock.
"I... I've never been hit on by a woman a hundred and fifty years older than me."
His honest bewilderment through the conversation is — and this is an adjective which no-one would ever attach to Harry Dresden — adorable. He keeps stuttering.
On the same note, Thomas berating Harry for not realizing that Luccio was non-verbally hitting on him.
"Moron. Thank God Nicodemus is a man."
When Harry is being rescued by Thomas at the end of the book, he makes a bunch of silly, petty complaints as Thomas respectively shoots Nicodemus's minions with a pistol at long range (He doesn't even practice.), hauls Harry up out of the water without any effort (He doesn't even work out.), and then walks back to the boat's wheelhouse, while looking awesome. (He doesn't even moisturize.)
Everyone seems to forget Harry's Genius Escape Plan that had me crying from laughter
Miss Gard brought the reconditioned Huey up from the eastern side of the island, flying about a quarter of an inch over the treetops, blasting "The Ride of the Valkyries"
Oh, and it had a Minigun!
Doubly funny when you remember that Gard actually is a Valkyrie.
Eldest Gruff has comes to kill Harry, and Harry asks Eldest Gruff why Summer (good) is apparently helping the bad guys. Eldest Gruff turns the question back on Harry, asking why Winter (bad) is apparently helping the good guys.
Harry: Gruff, I find myself largely clueless about why mortal women do what they do. It would take a wiser man than me to understand what's in a fae woman's mind.
Cue Eldest Gruff laughing his ass off.
This particular excerpt:
Mouse suddenly stopped in his tracks. Me too. I didn't rubberneck around. Instead I focused on the dog. Mouse's ears twitched like individual radar dishes. His nose quivered. One paw came up off the ground, but the dog only looked around him uncertainly. "Lassie would have smelled something," I told him. "She would have given a clear, concise warning. One bark for Gruffs, two barks for Nickelheads." Mouse gave me a reproachful glance, put his paw back down, and sneezed.
Difficult to notice on the first read, but before Harry heads out to the meeting with the Denarians he has to explain to Molly why she's unable to go with them stating that they've come to talk not to start a fight. Afterwards he heads into Michael's workshop where Luccio is explaining to Michael why he can't go, prompting a response almost exactly like his daughter's.
Fleeing Nicodemus's tongueless mooks through the island's forest at night, Harry nearly runs into one that can't see him very well in the darkness. The mook makes garbled sounds that seem vaguely interrogative, so Harry replies with similar garbled gobbledygook ... and flips the man off. He never does learn whether the guy'd fallen for his act enough to let him pass unhindered, or if he'd just shocked him into immobility with the rude gesture.