I own and use
CloneDVD2,
Nero Recode, OneClickDVDCopyPro, and DVD-Rebuilder Pro w/HC18. I prefer CloneDVD2 for quick and easy backups of average length movies for its speed, OneClick for hard to copy or larger movies and when I want the highest quality or movie is extra long (ie King Kong) DVD-Rebuilder Pro. Also, for one to one copies (DL) I like CloneDVD as it keeps the layer break intact.