I searched a lot, and there are just very few eventmanager avaible.

This one works best for me, but for me it lacks some important features to get 5 stars:

* User registration for non Joomla users (I solved this by adding a link to simple caddy)

All again, this plugin works like advertised, and it works well.

This shopping cart is very simple (hence the name), and also very easy to setup.

Since I want sell just some seminars, this cart is the best avaible for joomle. I can easily add an cart for an Joomla article, or in the eventlist plugin.

Freeway is very promising shopping cart. I wanted to use it's ability to sdll seminars. It would have everything I want:
-Event management (event can have multiple, selectable, dates)
-Good booking system
and it has much more to offer.

But:
In my experience it's just an very unstable developer version this time. I spent several hours to customize it for my needs.
Finally I gave up, because the bugs are lot, and some are very basic. I just added some content, disabled some boxes and the whole site disappeared (no frontend, sometimes the backend ist avaible).