Using symbols for controllers and actions


I am a newbe to rails. One of the things that confuses me is the usage
of symbols and strings to refer to actions and controllers. Which of
the following would be the right way to go:

<%= link_to ‘Login’, :controller => ‘user’, :action=> ‘login’ %>
<%= link_to ‘Login’, :controller => ‘user’, :action=> :login %>
<%= link_to ‘Login’, :controller => :user, :action=> :login %>

Or is it just personal taste? The last one probably spoils things

<%= link_to ‘Login’, :controller => ‘advanced/user’, :action=> :login

Any enlightments appreciated.

best regards