As your budget is like 1200euros
If you're going to be considering doing video editing, make sure you get:
1. i5 - it has a tech called quicksync which greatly reduces rendering time (up to 20x faster) - also, it has 4 cores and many games actually do use these.
1.b while you're buying - buy a haswell - why buy 3rd gen as people have suggested? It's just silly.
1.c never seen the need to overclock, but if you are considering it down the road, make sure you get the "K" version of the CPU. I personally don't ever bother with overclocking.
EDIT: I noticed Cyrops quoted a H81 mainboard with a 3rd gen CPU - er, no - different sockets. - Personally, I would go for the B85 chipset as I believe it has more USB 3 generally. No need to go wild with mainboards that have 2 x PCI graphic card slots, etc. SLI mainboards push up the price considerably.
2. nVidia video card - from my personal experience, the Radeon has more compatibility issues with games.
2.a If you are doing video editing, and you use two screens, one screen will be attached to the Intel on-board - this enables the QuickSync and also allows you to use this tech for watching movies, etc with almost zero effect on games on your main screen.
2.b If you aren't displaying more than 1920 x 1080, then more than 2Gb is a waste. More RAM on video does not necessarily equal more speed.
2.c A gtx 770 with 2gb of RAM is a good buy - I'm a fan of Gigabyte
3. Get a 256gb SSD - 128gb is a bit small.
4. Get a good 1TB Drive for your games
5. If you are going to be recording games, get a 2nd 1tb as a "scratch drive"
6. Get at least 16gb of RAM if you are doing video editing.
7. the corsair 200R is a good case and so is the 300R (more space in the 300R)
BTW - My favourite brands are corsair and gigabyte.