How about a different USB cable? I've have at least one that got damaged or worn and would not work on some device but would work fine on others.
It's unlikely that every Arduino in your neck of the woods is bad. It's more likely that it has something to do with your set-up. The common denominators are your laptop and the USB cable (I'm guessing on the cable, but it is cheaper to replace than your laptop).
Failing that, can you see your way to buying a new 328 with bootloader on it? There are places that sell them for under $5. If this fixes one of your dead boards, then you can use it to try to burn new bootladers onto the other two bad chips.