Oxiclean soak has always worked for me. And I never do it overnight, either. The dishtub I use will fit about six bottles. I submerge/fill each bottle one at a time and by the time I've submerged/filled the sixth bottle, the label is about ready to come off of the first bottle. Just keep rolling from then on.
Note that there are a few brands (Weyerbacher, Blue Mountain, etc.) that require a small thermonuclear device to get the labels off - even after an overnight soak. For those, I've found that one of those "single edge razor window sticker scrapers" will take the label off and then the bottle goes back into the rotation to soak off the glue.