Rad. My advice... I'm stupid but I also got a pretty hefty rig. and I built it for less than $1k. *Granted I didn't buy a new monitor...*
Go get yourself an AMD processor. Get an 8core. I use and recommend the FX-8320. Why not the 8350 you ask? Because I'm poor, but that is a decent buy as well. Why not the 9370 or 9590 you ask? BECAUSE THAT IS STUPID! It uses 220Watts versus the others 125Watts. You can have all that gloating power available on the market, but when that electric bill comes I'll be the one paying my car and electric bill while you're picking one or the other. Makes sense to choose the lower watt one and overclock or just be satisfied. Note, This line of processor is a step up from the phenom series. Unlike the FX predecessor. They switched their architecture and it had amazing results.
Get an MSI Motherboard, there is just no alternative. If you don't you're a bad bad evil person. Get one that is mediocre. Seriously you won't need the best of the best, DO NOT (I REPEAT DO NOT DO NOT DO NOT DO NOT DON'T!) Get that military spec junk. If you pay me $30 I'll solder some hard plastic on you're motherboard and shove it in an ammo can, that'll be REAL milspec (Junkier than anything you've seen is what mil-spec essentially is). Seriously it's a waste of cash. But my offer stands.
Video card, This is where you have to be the decision maker. Are you playing the latest games or are you playing CSGO, TF2... PS2... the games that can settle for a Radeon HD 7770. Heck I bought mine on Black Friday for $100. I'm sure it's less now. Or step it up to a newer version, I'd steer clear of NVidia... in my experience it's always been NVidia and Intel, and AMD and ATI(ATI is Radeon), In fact AMD now Owns ATi. The technology in the motherboard is the same as in the video card... all the tech is coming from the same building *Awesome idea especially in Mobile Devices!* Either way I'd just stick to ATi... if you're playing basic games then don't break the bank. Video cards go down in price quite often, as new tech comes out. Expect a $50-$100 drop every year on cards, maybe more.
Ram is where you don't skip, if you're building a 64 bit system then get a ton of ram. Why not? It's dang near Future proof, DDR3 ram will not be leaving us in the dust anytime soon. Yes the voltage does change from board to board, but almost all boards are backwards compatible. So Get 8GB at least, I got 16 in mine. Get a reputable brand too.
The Harddrive. Ok SSD... It sounds cool but GEE C'MON! My Win8.1 starts in from the push of the computer to the login screen in idk... 5-10 seconds... why would I care about solid state? Normally if you're hdd is running slow, it's because of malware in your computer, SSD is not even on my mind, it's expensive tech that I want more space out of before I consider it. I got myself 3.5TB of SATA drives. The Serial ATA keeps getting better and cheaper. GO FOR IT!
Case: The case is w/e. As long as it's a Mid - Full size ATX do what you will, now listen it HAS to be ATX, if you get another platform in case you may find out your motherboard won't fit... Doesn't have to be great or expensive, almost all cases perform well now days. Just make sure it'll fit what you're doing, consider the size of the processor fan, are you running watercooling? Will you be pouring Liquid Nitrogen to OC to 13GHZ (Ok I'm kidding... although it does get done quite a bit

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the MOST IMPORTANT thing if you discard the rest of my post *UNDERLINES THIS PARAGRAPH*
Power Supply, While building your computer get the total wattage of all your devices, make sure your power supply can handle the wattage PLUS some. Consider USB devices, Charging Cell phones, etc. nothing worse than a power supply that can't push the juice.
SECONDLY on this matter, if it says SLI or Crossfire technology... Just slap the store consultant for treating you like you're an idiot. To explain electricity pretty simply.... POWER IS POWER in this case. What that SLI and Crossfire junk mean is they have the connectors ready, however anytime you buy a video card it has the necessary connectors with it. Most powersupplies have it anyways... it's a marketing gimmick. So pay $110 for an SLI compliant power supply and I'll just laugh at you.
Now my last bit of advice. Look at refurbished. a Refurbished part is a new part that failed and was reconstructed with even more scrutiny than the normal underpaid assembly line worker. It get's redone by the one who makes .10 more an hour.... so you get a better quality device. Why on Earth (or Mars since we'll be there soon) would you pay so much $ for brand new when Refurbished IS new? That's like buying a brand new Mossberg 500 for $1000 when you're buddy who only fired 100 shells outa his is selling it for $300. You should be smacked for not being cheap!
I hope my long winded advice helps you. I've built about 5 computers now, and fixed a dozen others. I've even soldered a few computers back together including Honda Accord TCU's

Good Luck!