Try this program - http://www.geocities.com/marsoupilamis/DocEnglish.htm
It does probably the best job of any program that I've seen at extracting as much data as possible from bad discs like yours. It might take hours or days for it to run, but it will continually work at getting as much data as it can. You can also switch between each of your drives and see if one can extract data that another can't, let the disc cool down and retry, etc. It may not be able to extract all of the data, but it will get as much as it can - the parts that it can't extract will have visible defects in the video. The program is designed so that you can easily switch from one drive to another drive, and even take the disc to someone else's computer and it will continue to extract just the missing data, you don't actually have to have all of the already ripped data with you if you try it on another computer, you just need the .FLG file that ISOPuzzle creates. Some drives are better readers than others, so if you have friends or other computers to try the disc on, it might help. Read the instructions on the website I linked for more details.
You can also use DVD Decrypter and in the options you can set the amount of retries on read errors, but I've found this ISOpuzzle program to do a better job. At least with DVD Decrypter it can rip the disc files one by one, so you can rip the .VOB files that are not on the damaged area of the disc, then concentrate on ripping from the damaged portion.
P.S. - it almost looks like your disc is separating, it might be impossible getting all of the data off of the disc near the edge. Good Luck