If I were you I would upgrade most of the system.
Power Supply: GOOD
Video Card: Slightly outdated but can play most games at low settings. I would reccomend upgrading to a GTX 960 or if you have extra budget a 970 or 1060.
Memory: 8GB is fine but if you can upgrade to a 16gb kit. Make sure to either get a new 16gb kit or get the same 8gb kit to extend it.
Motherboard: Depends on CPU so its fine in this case
CPU: I reccomend an upgrade to the Skylake platform, maybe a i5-6500 or even i5-6600k if you plan to overclock.
Motherboard2: Since you would upgrade your CPU to a Skylake processor you would have to get a capable motherboard. Read this it might help
http://www.trustedreviews.com/best-motherboard_round-up
Read the B150 section as the B150 chipset is more budget oriented if thats what you want.
Hopefully this helps!