depends what you want to do...
Wordpress is great for the blog style and is easy to mod.
But if you want more on forums joomla and wordpress both suck...
SMF forums has a portal and lots of addons that you can use to turn SMF into a pretty good CMS, easy to install / mod.
Most CMS seem to be a real pain to intergrate forums and blogs into properly so a heavily customised forum may work better for you depending on your aim of the site.
phpbb and mybb can be customed pretty easy too.