I have several different content type nodes (videos, image galleries, stories...) that I would like to categorize and create a top-level page that aggregates these nodes. So for example, the top-level page would have teaser thumbnails very similar to the front page view but of course filtered for that topic (like for instance automobiles, and motorcycles would have its own page, etc...).
What is the best way to accomplish this? Taxonomy? Views?
You would use both Taxonomy and Views.
Taxonomy would categorize the content, and Views would allow you to configure the display however you like.
One possibility is having an Argument of a taxonomy term, (example, /path/path/taxonomy-term/index.htm) where taxonomy term is a passed URL argument. This would filter all content to that term.
You could also just rely on the taxonomy system, where content resides at /taxonomy/tid, but I don't think you get much control of the output that way.
You may also want to look into a module like Taxonomy VTN for a drill down list of taxonomy:
http://drupalmodules.com/module/taxonomy-vtn
There are lots of ways to approach this. Personally, I would use Views.