Q:

How can I create a Base Class for all my modules in Zend Framework

I was thinking to create a generic base class and have each of the module base class inherit from it... but is there a better way to do this? 

A:

I'd say if you need a base class, you're not having real modules.  I think modules should be "totally" independent sub-applications.  
If you really want to write such a base class, use dependency injection, not inheritance so you can inject the needed common behaviour in all modules without creating such a tight coupling of all your modules.  Just create a subfolder under 'application' and call it 'Base' or something.  But again, I think it might not be such a good idea resp.  if you need it, we're not talking about modules.  Then again, each case is different.