Build a PC Whats Parts Should I Upgrade?

Vluss

TS Rookie
[SIZE=4]Hi I recently purchased a new computer and I wanna upgrade some of the parts. I would like to be able to run faster and be able to record games so what would be the best to upgrade for that?
SYSTEM SPECS:
Case - Rosewill ATX Mid Tower Computer Case with Dual USB 3.0 and Four Fans
CPU - Intel Core i7-4770K 3.5 GHz
Motherboard - ASUS Z87 PRO LGA 1150
CPU Fan - Cooler Master Hyper 212 EVO
Video Card - EVGA GeForce GTX 780
RAM - Crucial Ballistix Sport 16GB
SSD – Crucial M500 120GB
HDD - Western Digital Blue 1TB
Case – Cooler Master HAF 912
Power Supply - [/SIZE]XFX ATX 550 Power Supply[SIZE=4]
Optical Drive - Samsung 24x SATA DVD RW[/SIZE]