Possible Clues:

• You'd very much like to have no better finish to a Friday
• Closest pal
• There's no better way to finish Friday than be with one
• Such a very good finish to Friday is close to one
• A dog will be, somehow, first to last
• One to hang out with
• The last of Friday could not be better
• Milhouse, to Bart
• Bosom companion
• Mate for life?