Experimental: Example, A free-form exploration of an abstract concept where the normal rules don't apply.
Music Video: Example, A performance video set to music-- there are a wide range of styles within this category.
Text / Graphic: Example, A video using animations, words, and symbols to get meaning across. Often informational, although it has many experimental qualities.
Subvertisement: A "subversive advertisement" criticizing an assumption or anoverlooked problem