Wordpress is my CMS of choice these days. I've found it to be more or less the easiest one to work with, find plugins for, and customize.
By default, wordpress does not use smarty. You must either be using a template that specifically integrated smarty, or a 3rd-party plugin that includes it.
Here's a couple articles on wordpress theme development:
As for other CMSes, there's also Joomla, Drupal, and ExpressionEngine. However, I've found Joomla's plugin and theme systems to be hard to work with.