Need help with upgrades!

I have had my pc for a couple of years and have upgraded slowly over time, but probably not as efficiently as possible. I am looking to increase the general snappiness of my pc as long as increase frames and whatnot. I play a lot of game and watch YouTube and such, no photo or video editing to speak of at all, if that is a factor. I am planning on getting an SSD so recommendations for upgrades and what specific parts to purchase would be much appreciated ^.^.

My Current Build:
CPU- Intel Core i5 4690K at 3.50 GHz.

Ram- 8.00 GB Dual-Channel DDR3 at 799 MHz

Motherboard- Gigabyte Z97X- Gaming 5

GPU- NVIDIA GeForce GTX 1060 6GB

Storage- 2794GB Seagate ST3000DDM001-1ER166 (SATA)

Sorry if some of this is redundant, just wanted to be as clear as possible. Thanks for any help!!!