Are there a few templates out there?

wondering if there are a few more "templates" out there for the JEM easy list for example. So are there a few other sample css files out there?

There probably are some made by users, but not here at the site.

It's all controlled by the css/jem.css file?

yep, but you can use custom css.

The one provided in't suitable for most sites

then the question is: how do you like it to see?

best you have it in the same folder (media/com_jem/css/), then you don't have to change image addresses.
And perhaps you need an override. That means you have to copy common/default_events_table.php to the html-folder of your favourite template
(/templates/my_template/html/com_jem/common/default_events_table.php)
This is better than changing on the original file.

it depends of what you want or how much you want to change.

Why not simply make a JEM setting where I can set my css file?

would say: hang on and see what 1.9.7 brings