There is no doubt that all the lean tools are useful in different different purpose. Challenge is how you are using those. If you are in the initial stage of implementing lean, you should start with 5S - simple and powerful tool of lean. Even when you will start 5S, please please please, don't use all the five "S" at a time. Just start with "Sort". Then one by one.
Another powerful tool is Kaizen. Other tools are VSM, Jidoka, JIT etc.