I dont think there is one. If you made a Nandroid then you could just restore the /system partition and that should restore it to normal. If not then I believe your only option to use stock again would be to do an RUU as I don't think there's any stock roms that can be flashed. Well there may be but I never found one. If you're okay with doing a custom ROM then I'd recommend CleanROM or Android Revolution HD, both are stock but with tweaks and optimizations.
If you still wanna go with stock then to keep ur stuff just back it up with titanium backup and turn it into a flash able zip and backup ur internal storage to a computer or something then do it and when you're back on stock go into your recovery and flash the zip. Once you also restore your internal storage and do some re-organizing everything should be back to normal.
BUT research yourself first, there may be a way to do that without doing the complicated process of an RUU. Anyways Goodluck with whichever thing you choose to do!