Hubpages used to have a "success stories" page, but it seems to have disappeared. I think when Google changed some time back and a lot of those successful hubbers had a severe drop in their traffic, HP was forced to rethink their strategy for recruiting new HP members and couldn't simply rely on those HP stories anymore.
I'm not sure if any of those writers are still on here or if they've ever regained any traffic. Your best bet would be to snoop around in the forums. Simply type "HP success stories" in the search field above and you can find numerous forum posts and previously asked questions regarding former HP successes..Although most of the posts are from quite a while ago.
If you start to spend a little bit of time in the forums, you'll see there are still quite a few Hubbers with a lot of followers and a significant amount of quality hubs published. However, I think the old days of the HP success story that drew most of us here (ex. "Patty so and so makes 1/3 of her families income passively by writing for Hubpages!") is long gone.