I was about to start a new build with your budget, but decided to wait until the next gens tech come out (DDR4, 880 series, new Intel chips), but it's just because i'm satisfied with my current rig. I agreed with all the other builds above, but i personally prefer i5 over i7 (very minimal differences but nicer on price) if you're on strict budget (if not, then i7 is fine), take out the OS system, and buy a brand name PSU like seasonic instead of rosewill for a peace of mind. Also, if your budget is strict, then i recommend not buying the HDD, but put all that money into a 240/250gb SSD for convenience (my SSD lasts longer 3 years already). I made the same mistake before buying a 120gb SSD but the capacity is too tight for OS and even only couples game, since recent games size are ridiculous. Later, you purchase a HDD down the road (recommend buying 3tb, I got one for only $100).
That's about it. I strongly recommend you building it yourself (or with friends), and trying to find bargains on Ebay (new only) if you can, but don't be cheap. DO NOT BUY USED STUFFS (at least not now) because it's a pain to spot the broken piece when you start out. In my experience, used stuffs will end up costing you more money and headache if you don't know what you're doing.
By the way, I hope you have some dough to get a nice monitor (around 200-300) and again don't be cheap on it. Monitor is your eye and your experience to the world everyday. If you're tight on money, you can change gtx 780ti to gtx 780 and use that cash for monitor. Just my 2 cent.
Check it out and have fun !! ^_^
CPU: Intel Core i5-4670K 3.4GHz Quad-Core Processor ($179.99 @ Micro Center)
CPU Cooler: Cooler Master Glacer 240L 86.2 CFM Liquid CPU Cooler ($114.99 @ Micro Center)
Motherboard: Asus Maximus VI Hero ATX LGA1150 Motherboard ($189.99 @ NCIX US)
Memory: Corsair Dominator Platinum 16GB (2 x 8GB) DDR3-1866 Memory ($204.99 @ Amazon)
Storage: Samsung 840 EVO 250GB 2.5" Solid State Disk ($153.95 @ Newegg)
Video Card: EVGA GeForce GTX 780 Ti 3GB Video Card ($709.99 @ Amazon)
Case: NZXT Phantom 530 (Black) ATX Full Tower Case ($129.99 @ Newegg)
Power Supply: Corsair RM 750W 80+ Gold Certified Fully-Modular ATX Power Supply ($119.99 @ Amazon)
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-04-19 02:38 EDT-0400)