I used Handbrake (free) for about half a year. Though it can rip DVD to almost all mainstream formats, some of my DVD can't be readed with it. I was going to pay for a powerful DVD Ripper, while I came across WinX DVD Ripper Platinum Giveaway on giga.de I've hearded this software before, so I download it, works faultlessly and effectively. And I'd lke to share it with you guys to solve DVD ripping & backup problems:-)

You can get the giveaway for windows Giveaway - Free Get WinX DVD Ripper Platinum
or if you're mac version http://www.winxdvd.com/giveaway/giga-mac.htm

Ps: this giveaway will be ended on Oct.19
Hope this tool comes in handy for you!