If you are getting CRC errors trying to rip or copy a disc then there's most likely a problem with the disc... less likely a problem with the drive but it's still possible.  I think a CRC error being the fault of a particular application failing to read a perfectly good disc properly is unlikely but let me know if you find out different :)
http://www.tech-faq.com/data-error-cyclic-redundancy-check.shtml

MattMan is the only person I would listen to when it comes to DVD ripping software - and ripping= taking the DVD video and converting it into a .avi file or some other format playable in whatever media player you use on the computer or a portable media player like a Zune.  #1 Matt's a noob and doesn't like anything too complicated.  #2 he's been making copies of DVDs for his kids for a long time - I'm disappointed he didn't have anything to say here.  Nero sucks.  DVDshrink is pretty great for copying from one disc to another disc - the 'shrink' part of the name refers to shrinking a DVD9 (9.4GB) to fit onto a DVD5 (4.7GB) by removing extras and/or re-encoding the video at a lower bitrate to get smaller file sizes.

DVDDecrypter is/was one of the best apps for stripping the copy protection off of a DVD and making a duplicate disc.  The guy who made it stopped including that functionality due to legal issues and today the app is called ImgBurn: http://www.imgburn.com/ - http://forum.imgburn.com/index.php?s=c6454dae3721515f40bacd11eae31fef&amp;showforum=4 = guides for ImgBurn - and that is what's best when it comes to DVD and CD burning and it's dead-simple to use for most things IMO but I don't think it will be able to make copies of retail DVD video because they no longer have copy protection removal built in... fuck Nero and it's bloated bullshit Nero hasn't been any good for years now IMO.  Nero peaked when they bought or stole (not sure which) DVDShrink and went downhill from there.  There's just too much crap you don't need installed and always running when you use the full version of Nero and the lite or free version is too limited.

All my ranting aside... what is it you're trying to copy?  Bit Torrent to the rescue?