I noticed that my 3 and 8 year old children tend to remember to wash their hands when we have a fun soap to use. I have tried many brands and Softsoap seems to be the best. The pump works well and never sticks and the soap smells good too.
This time I bought the 7.5 fluid ounce bottle of SpongeBob Square Pants Foamworks soap. My kids were excited when they saw it on the sink and my 3 year old immediately had to wash her hands!
You really only need one squirt (I wish I could convince my kids of this) because it lathers up quite well. The scent is subtle and fresh so an adult doesn't mind using it either! The bottle seems to last a while, but I haven't figured out how to refill it yet. I wish they sold refillable soap for this so that I wouldn't have to waste the container and purchase a new one each time.