SPECS:
Core i7 4790K
Asus Sabretooth Mark 2 motherboard standard ATX
Nvidia Geforce GTX 780 GHZ Edition
8GB Corsair Vengeance Ram
250GB Samsung SSD
1TB Caviar Black Drive
Windows 7 Ultimate 64Bit
Coolermaster V1000 PSU
And what could i improve apon
He knows he has a high end system, though he failed to mention his monitor (resolution and hz in particular). Depending on the resolution and target FPS, he won't play all games at max, but isn't required to be considered high end.
it depends on screen resolution you want to set... if you want to run it at 720p/60fps, then your specs is way to go... for 1080p/60fps you should upgrade your GPU to SLI mode... for 1440p/60fps you should upgrade your GPU to gtx 980 SLI... 2160p/60fps is still a dream...
Your pc will run high-end games, but make sure you run the game from the ssd. That will boost up the loading time, level changing, and any other parts of the game where disk is used.