I voted CM Punk, Cena, Jeff Hardy, HHH, Undertaker, Christian.
In a perfect world where these guys are as good authors as Jericho, mind you. CM Punk's would have to top the list, because there's a lot about his story that I don't know and I think would be worth hearing. Jeff Hardy has a lot of demons, and I wonder if he'd own up to them and what got him to the point of being so hopelessly drug addicted. Triple H - duh! He's one of the most controversial backstage figures of all time. With Christian, most of his story is told by the stuff he did with Edge, and even though both of their stories are quite obviously very intertwined I want to hear it from his POV.
I'd read the Undertaker's, but it would probably be too mind boggling to swallow
I'd also really like to read another Edge book, which I hope he comes out with since his first one came out before he had even won a world title.
He's been asked about it and says it's definitely a possibility. It had better be. The way it cuts off literally right at the moment when things start getting really interesting is such a tease.
Vince's would be the ultimate wrestling autobiography though
Aw, man. I never even thought of that, that would most definitely be one of the best.