Shopzilla has quietly, but dramatically changed the way it presents search results to users.

Big bold pictures highlight the change in this search for Football (Go Giants!):

As opposed to:
Pricegrabber

Yahoo! Shopping

Shopping.com

Furthermore, Shopzilla is delivering detailed categorization to help the user narrow results.

For example, the main page of Home Organization lists Storage Product Type, Closet Organization, Garage Organization, etc.:

And drilling one level deeper on Closet Organization reveals options such as Shoe Organizers, Hangers, and Closet Rods:

Shopzilla’s taxonomy only has ‘Home Organization’ (25000800) as an option, so they are doing a solid job of going deeper than just what merchant specifies as the proper category in a feed.

While this taxonomy work isn’t anything new for the shopping engines and Shopzilla still has a long way to go, Shopzilla’s filtering options just seem to be a little sharper/cleaner than what’s found on the other shopping engines.

Examples:
PriceGrabber - Home Organization
Shopping.com - Home Organization
Become - Home Organization
NexTag - Home Organization
Yahoo! Shopping - Home Organization
Smarter.com - Home Organization
Sortprice - Home Organization
Pronto - Home Organization
Google Product Search - Home Organization

Starting with the big, bold pictures representing the categories and then moving down into cleaner/more robust filtering options and a more granular taxonomy, shoppers should be finding products easier (which makes for a better shopping experience) and merchants should be getting more relevant clicks (which improves ROI).