I use the Diztronic Soft Touch TPU case. I feel that it is very comfortable to hold, not too much added bulk, not slippery at all, and I am comfortable with the amount of protection provided. It costs ~$10

Link - Galaxy Note 5 Case, Diztronic Full Matte Flexible TPU Case for Samsung Galaxy Note 5 - Black (NT5-FM-BLK) https://www.amazon.com/dp/B012TZ9ZMM/ref=cm_sw_r_other_awd_CBktwbXRCRWT4