Soap (any soap) and water will remove germs, oils and dirt from the skin whereas hand sanitizer containing alcohol are meant to kill germs but are not very effective if your hands are not clean because oil and dirt essentially protect the germs from contact with the alcohol in the sanitizer. That's why soap of any kind and water beats hand sanitizer.
Here is some disturbing news, according to the article linked below hand sanitizer doesn't do much to kill Norovirus. In fact rinsing your hands in water alone is more effective against Norovirus than hand sanitizer according to this study.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805232/