For 1k it isn't so bad. I highly recommend newegg, I've been ordering from them for years and they're great.
Anyways
http://www.newegg.com/Product/Product.aspx?Item=N82E16883227408
That right there has your more than standard RAM sitting at 8GB dual channel for more multi tasking.
You've got 8 cores for a CPU, very powerful for gaming and is amazing for multitasking.
Decent hard drive capacity to store whatever you like.
A pretty decent dedicated video card that will get you able to play pretty much every game out there on some nice settings.
Everything you need for an all around decent starter PC for gaming is all in that one box, anything higher end will cost ya alot more. Good news is that PC can be upgraded as it's got a custom fitted motherboard and not some stock cheap junk that's locked up tight from tweaking or upgrading...
For anything else you might want to throw in for accessories, try something like along these lines to add in...
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236153
http://www.newegg.com/Product/Product.aspx?Item=N82E16826104261
http://www.newegg.com/Product/Product.aspx?Item=N82E16826153055
http://www.newegg.com/Product/Product.aspx?Item=N82E16823114004R
http://www.newegg.com/Product/Product.aspx?Item=N82E16823114012
http://www.newegg.com/Product/Product.aspx?Item=N82E16826104281
http://www.newegg.com/Product/Product.aspx?Item=N82E16826104399
All good stuff xD
All that is just a basic example of things you may want to get or things to look for if you want to get started with a gaming PC. Accessories matter just as much as the system itself sometimes, I swear lol