Cola. Really. I regularly use baking soda in the wash, then vinegar in the final rinse. This combination works for your average, garden-variety, I-wore-this-shirt-today odors. But for really tough odors, add a can or two of cola to the wash water and launder as usual. I picked up this tip here on Thrifty Fun and have been using it ever since.
The thread where I first read this is called "Homemade Febreze Laundry Odor Eliminator". Type that into the search box; it's the first entry listed. ... View related article.