What tool do you find most interesting to date?

Personally i find the Pen Tool most interesting. it allows me to recreate an image by tracing it in a shorter space of time rather than if i were to just the pencil tool to draw it. Also it makes it easier to do curves on the edges of pictures as you can simply hold down the node and turn it to your liking to get the curve you want. So all in all the pen tool makes it tracing images quick and easy and its quite accurate