I'm still rocking a Nexus 4, and the Note 5 looks like the change I've been waiting for. I would definitely put the awesome 16 MP camera to good use on the Android Central Weekly Photo contests! Also, I take lots of notes and the new note taking feature @chodaboy referenced with the screen off would really come in handy.
I'm most looking forward to using the new stylus. First, to help me create a shopping list to feed the bottomless pit stomach of my teenager. Secondly, to perform my "pen going up my nose" magic trick for my toddler.