Cal doesn't read for pleasure. He reads to learn stuff, and now that he's on a world that's in the twenty-first century, the internet is way better for that. Though in the event he wants to learn something important, he's still likely to default to reading books. They are just more important-seeming and serious. With all that said, his favorite is his son's autobiography, because he finds it reassuring even though he knows full well that a lot of it is probably fabricated/polished up to appeal to the public. Some of it still has to be true; the Chandlers are too famous for Calvin to have gotten away with really obvious lies.

As for other pups' canons, Cal learned the hard way with Chandler Bing that knowing stuff about a person that they haven't told you is invasive to them and creepy-feeling to him. He can't unwatch/unread stuff, but he can avoid encountering new canons - he's being very, very careful about doing so with the Harry Potter series, for example, since he's friends with Hermione. Potter pups need never worry about canon-puncturing from Cal! Neither does anyone else, for that matter. Doing it to Chandler was enough of that for a lifetime.

Javert doesn't like to read, but he does it anyway during what little downtime he has, because he can't stand to let his mind be idle. But since he doesn't like it, he doesn't have a favorite. Someone needs to teach him how to play chess or something.

Applegate doesn't have time to read, are you kidding? Do you know what the Devil's workload post-industrial revolution/population explosion looks like? He is rather fond of certain passages from Genesis, though.