The Bootstrap template for Zen CartI am a big fan of the Zen Cart Bootstrap. I use it on my own store, and I strongly recommend its use, since it is the most up to date and well maintained template available. It is also accessible out of the box (subject to your content and color choices, of course).
You can see examples of bootstrap on my store and on a test installation with the Zen Cart demo data.
Here's my store on desktop and iPhone:
And don't worry - many design elements can be added to the base bootstrap template if you want them. Let's look at some:
Horizontal menu with DropdownsCustom dropdowns can provide more options than either the Categories-Tabs menu or EZ Pages header bar.
Flexible FooterMany storeowners love the Flexible footer plugin because of the ease of updating it provides.
SlideshowsSlideshows are no problem to integrate.
You can read more about the bootstrap template on the Zen Cart documentation site.