One task that every one should do it is deleting useless files. If you do not, you will run out of disk space inevitably. Then, you will wonder where my disk space has gone?
Filelight is the answer to you. Filelight creates an interactive map of concentric, segmented rings that help visualize disk usage on your computer. Like a pie-chart, but the segments nest, allowing you to easily see which files are taking up all your space.