Depending on where you're starting from will determine what you can see. If you're starting from the south end all the usual places.............Rainbow bridge, etc.....
With only 5 days you will not be able to see everything. I spent 8 days and only saw about half the lake. The best thing I can suggest is just explore way up the end of the arms. You will find yourself all alone with no one around. You can hike back into the canyons and see all kinds of spectacular views.