Kristen Stewart was a well-regarded former child star when cast while Robert Pattinson had a Harry Potter fanbase. Both have gone onto other interesting, high profile projects. Taylor Lautner did a movie too. Meanwhile The Hunger Games' Jennifer Lawrence was Oscar nominated for her role in Winter's Bone and appeared in X-Men: First Class. Josh Hutcherson has acres of kid/teen roles behind him and Liam Hemsworth has a tween following thanks to the likes of Neighbours and The Last Song.
Winner: Hunger Games, at the time of casting at least.