Get one of those Disc Doctor/Game Doctor resurfacing devices. That way if you can't find a rental, you can at least repair your original to the point where you can get a good image on your PC to dupe it.
Nero, Primo/RecordNow, Alcohol 120, and DVD Decrypter are the apps of choice these days. Image it to hard drive, then burn it. Read the stickies up top. Most of the "how to's" and stuff should be covered there--or at least links to sites that can help you.
If it ain't broke don't try to fix it! But, hell if you can tweak that bastard just a little bit more....hehehe.