Reading outside is the best.
I've tried to keep a running list this year of our read-alouds and audiobooks. Approaching the end of the year (not ready!), here it is:
Ramona the Pest
Ramona the Brave
Ramona and her Father
The Mysterious Benedict Society
The Bad Beginning (Series of Unfortunate Events #1)
LOTR: The Two Towers
Ramona and her Mother
The Reptile Room (SUE #2)
Story of the World (Ancients)
The Mysterious Benedict Society and the Perilous Journey
The Phantom Tollbooth
The Wide Window (SUE #3)
Some of these, like the Story of the World, we listen to at home (and not in order, we used it as topics came up in our studies - still can't believe they liked it this time - so much!). Others we listen to in the car - very useful for boys who have to shuttle back and forth to drop/pickup siblings. A couple I read aloud to them, and the Lord of the Rings series is their dad.
Audiobooks are great for those books that you KNOW they'll like, but they are too stubborn to pick up themselves. I'm not sure Monkey would have read many Beverly Cleary's if we hadn't listened to a Ramona book first - and now he likes that author (of course he does!). His sister has been trying and trying to get him to read the Series of Unfortunate Events, but he won't. So I picked up the audiobook 'for his brother' and he has to listen since we're in the car. And he loves it. But three books later he still won't admit it even when I hear him laughing! And it's good for my redheaded reluctant chapter-book-reader. Delays + vision learning problems means his confidence falls short sometimes, though he is a good reader! So a big thick book isn't as overwhelming when you have it on audio.
If not in the car, fiddly toys, coloring, playfoam, or something to keep their hands busy while they listen works wonders.