DVD-Lab Pro <This is my first choice! I love this program!
Scenarist
DVDit!
DVD maestro
ReelDVD
Even IfoEdit has an authoring option
Etc.
It seem Warner uses a Panasonic LQ-VD2000S to author seamless branching dvds.
If you've made a branching dvd you can make it seamless with TFDVDEdit, or so I read. But's it's for MAC OS.