Google Reader is to be shut down on 1st July 2013. Here are some alternatives:
Feedly - works perfectly with Firefox and has an app too. Pretty much all Google Reader features are available (keyboard shortcuts included) but lacking right now is the ability to search over posts. Is not compatible with IE8 (for those which still have it).
TheOldReader - looks very similar to Google Reader with similar features. Great alternative. Not compatible with IE8.
See also:
http://www.rba.co.uk/wordpress/2013/03/14/google-reader-what-next/ (Karen Blakeman )
http://philbradley.typepad.com/phil_bradleys_weblog/2013/03/20-alternatives-to-google-reader.html (Phil Bradley)